Selling electronic components in a retail setting is just not viable. To cover costs and make a profit the prices have to be so high that people are quite rightly going to begrudge paying such high prices. As a result you end up with a reputation of being overpriced and lose customers. There are a few stores that sell a good selection of components at a reasonable price but these tend to be small independent stores run by enthusiastic owners. The owner typically owns the premises having purchased it many years ago at a low price or has a long standing low cost lease helping keep the costs down. They are probably also content to simply earn a living rather than having the demands of producing a profit for shareholders. The sad thing is that if they do own the building they could probably make more money by selling it or renting it out than they do from running their own electronics store, chances are when they retire that is exactly what will happen as nobody else will want to take on the hard work of running the store for such small returns.
Some of the reasons why it doesn't work...
Sourcing
Let's take a simple example like the ATMEGA328P as it a microcontoller that is popular enough to warrant being sold in a retail store. Where are you going to get them from? If you thought direct from ATMEL (Now Microchip) you would be severely disappointed. Large manufacturers already have their established distribution partners, and they are often strictly limited to one or two in a particular region. If you want to become a distributor then typically you are expected to carry virtually the whole range from a manufacturer including obscure products in BGA packages etc that are never going to be suitable to be sold in a store. You are also expected to have a significant stock holding, the manufacturer doesn't want to be directing customers to buy from somewhere that never has any stock. Unlike consumer electronics or computer products there are no wholesale distributors serving the retailers, and you can't risk buying from unknown sources on eBay or Alibaba as you need reliable traceable sources. So your only real option is to negotiate some small discount with a distributor but it is not going to be enough to support costs associated with retail.
Handling
So you have found a distributor who is willing to offer you a discount but your components arrive in a bulk bag, tubes, trays or reels. You are not going to sell them like that, you can't just hang the tubes on the wall and leave customers to open the tube and take some out. So either you have a counter service where the person serving must locate the correct item, count out the number required and package them up or you split the bulk package into individual items or at least packs of small quantities. So assuming you create retail packs, it could be simple bags or perhaps something a little more presentable like a blister card. So now you have to add the cost of the packaging materials and more importantly the cost of paying someone to do this, in Taxas where RadioShack were based that is $7.25 per hour minimum wage. Suddenly the cost of your part has doubled just due to re-packaging and labelling it. But your costs don't end there, to get the discount negotiated with the distributor you have to buy in large quantities, perhaps 5000 at a time. You are unlikely to sell 5000 in a month to your hobbyist customers who are just picking up a couple for a project they are planning for the weekend. So now you have to store the extra stock somewhere, warehouse space is not free. Finally you have to send these items to individual stores and replenish stock as required, that is again either shipping costs or staff/equipment costs for having your own drivers delivering to stores. So now your component is at least 3 times the original cost.
Space
Retail store space is typically quite small, it is virtually impossible to have a wide enough range for the convenience. Should you stock PIC, ATMEL, ST, NXP or TI microcontrollers? The more you stock the more space you need and the more suppliers you have to deal with and try and negotiate discounts with.
Overheads
We hear a lot about this one, that retail is expensive. Well you have a number of costs such as energy for heating, lighting etc but such costs are insignificant compared to the two main costs that are floor space and staffing. In the US the minimum wage is anywhere between $7 & $10 per hour so if a store employee is helping you with your purchase even just spending 10 minutes to show you where in the store to find microcontrollers and take the payment from you that has cost a couple of dollars in time. The cost of your floor space is determined by your rent and taxes, it costs the same to have a small tray of a dozen microcontrollers in your store as it is an iPhone. Assuming you are paying minimum wage you are not exactly going to get the most talented staff, to them it is just a job that helps pay the bills. If they had any significant interest or skills in electronics they would likely be either working somewhere better paid or working in a much more interesting job.
The bean counters that run these companies have a very simple way of working out what to sell and how profitable it is...
Cost price, i.e how much each item costs by the time it reaches the store. So our $2 ATMEGA has cost $5 to this point.
Cost of Sale, i.e the average cost in staff time, transaction fees etc that it costs to sell this item. Lets add $1 for arguments sake.
Cost per Sq Foot, In order to cover the rental costs items must sell a certain number per month. All of the items within a square foot of floor area must sell enough to cover the rent for that space.
Profit margin, in addition to those costs there must be a profit margin to grow the business and pay shareholders etc.
So would you pay $6 for a $2 microcontroller that you could probably even pick up 10 from an unknown eBay seller from Hong Kong for $10? You probably wouldn't, I know I wouldn't. So what do the bean counters do?
Well the problem is your $4 costs create a 300% markup on this little $2 component and as a result your already limited sales volume is reduced further by the lack of customers willing to pay those prices. However it doesn't cost significantly more to handle a tablet or a smart phone, only this time your $4 handling cost only represents 2% of the price of a $200 tablet. Far fewer people are going to be bothered by an extra 2% and there is a much larger potential customer base for such a mass market product that is likely to sell much quicker than components would. The solution therefore is simple, if there are enough customers still buying components at the very high prices then keep those items, otherwise drop them and sell something else that does make a profit.
The bottom line is that the low price of components coupled with the high employment costs and property (real estate) value simply makes selling components in a retail environment uneconomical. Electronic component supplies only really work as an on-line business.
PS thanks for all the support and good wishes.