One word "Guitarfetish". Cheap and good sound look in the blowout section.
Here are my thoughts. If your overall goal is to actually use STR-52 pups, there are a couple of ways to approach it. You could do the build for two pickups and only install one in order to get it playable. You could make a cover of some type to hide the other cavity until you get the funds to buy the second pickup and then upgrade at that point. A possibly better way is to build your guitar with cheaper pickups. You might be pleasantly surprised and leave them in. If not, you could upgrade by replacing one cheap pickup at a time with an STR-52 and then you could use the cheaper ones in future projects. If you aren't already hooked you will likely find that building these things is highly addictive. I've installed "cheap" pickups in all my builds to date and have to admit I haven't been at all disappointed in the tones I've been getting. There is so much variability in woods, placement, setup, strings, and such that the most expensive pickups in the book could sound terrible. I hope this helps... See Ya!