For $99.99 (Radio Shack) you might want to take a look at other options. Like the PICAXE from Revolution Education...also free software and manuals, and only requires a serial cable:
Once you start using the BASIC Stamp in projects you will find that they are very expensive one-off. It's a very good µP...just expensive.
The cheapest are MicroChip PICs. The PICAXE and BASIC Stamp use these but with onboard software. Dirt cheap chips...but require a hardware programmer.
Lots of choices out there and trade-offs on all of them.
Ken