If you can't appreciate the difference between cheap parts and expensive parts - in terms of build and feel, then you wasted your money. Either way, building a bike is not an investment. You are almost guaranteed to lose money on resale, unless you are buying parts at or below cost.

I've built up everything from a $50 Salvation army Special to a $4k Indy Fab - I've always gotten a reasonable return on resale, but I always end up losing money. The two high end SS bikes that I've built and sold - a custom Cannondale and a Ventana SS MTB, both sold for reasonable money. I didn't do any better or worse than with any other bike I've sold. In fact, the market for SS/FG is still pretty hot, so you have a better chance at resale with these types of bikes than, say, a 26" hardtail MTB (speaking from personal experience).