Since I've shipped into a number of EU countries.....on the whole, yes the German customs tends to be the most difficult to get packages through, it also depends to some degree on which customs in which city it goes through, some are much more difficult than others. I'm told there are fees on top of fees and the ever present VAT. The dollar value for no significant fees is about $20, that is meant to make sure very little comes into the EU without being nailed and makes it more difficult to fudge on the value a lot. They are also very suspicious of too many samples or of what looks like very low pricing, that may or may not trigger a customs battle. I do not know of any customs free duty on PWW resistors in any EU country, if there is none of my customers has mentioned it. You might be able to get away with shaving some of the actual costs off of the customs paperwork for reduced fees/taxes but it can't be excessive.
Each country tends to be different in how they handle customs, there doesn't appear to be any universal rules being applied outside of perhaps the VAT. I would presume once the resistors are 'inside' the EU, there would be no further problems/charges/fees on distributing them to other countries outside of postage. It would only be a matter of checking around with EEVblog members to find the lowest cost entry country.
I also give pretty good quantity discounts......end of ad.