Where to get long pre-crimped leads?

[Phoxtane]

My project is a signal board for model trains, and I've opted to use the incredibly common generic .1"-spaced right-angle pin headers as opposed to screw terminals in order to save on cost per board. However, this now means I have to equip each cable with the appropriate crimped connectors. I need two shorter cables with a length of about 6 inches, one with three wires and the other with four, and a third 24 inch cable with four wires. I've been attempting to crimp my own cables, and while I can produce a useable end product, the quality leaves something to be desired, and it's incredibly frustrating to make the crimps and insert them into the housing in the first place.

I therefore started looking for pre-crimped leads, and quickly found the Pololu website, which is perfect in that I can choose from a wide range of colors (perfect for keeping the purpose of each wire clear) and comes in the lengths I'm looking for. However, I have discovered that the prices are quite high; $2.49 for a 10-pack of 6-inch cables, and $4.49 for a 5-pack of 24-inch cables!

Therefore, I want to tap into other's experiences to see if there's a place to get pre-crimped wires on the cheap in a fairly large range of colors and of decent lengths.

As a side note, I've noticed that many of the DCC-enabled trackside accessory boards have the ubiquitous green screw terminals instead of pin headers, even though the cost for these connectors is much higher. Is this because it allows the buyer to use whatever length of wire they want? I suppose the additional height of the board doesn't matter as much as the buyer can embed it in their foam scenery or under the bench without much trouble? In light of this, should I keep going with the pin headers or move to screw terminals?