More parts purchased, at Radio Shack:
A DPDT rocker switch - $4.35 (tax included)
A PC board for resistors - $4.00 (tax included)
Roll of hook-up wire - $7.20 (tax included)
Total cost so far: $70.50, and still no LEDs purchased! Of course I had to buy a little soldering iron and some solder, too, but those don't count, being "tools".