All,
FYI -- My local not-so-aptly-named "Dollar Store" had cheap pencil soldering irons for $2. Many folks have recommended soldering irons for melting drain holes in plastic cups and deli containers for growing out cuttings. (It works great!) I've never seen them that cheap anywhere.
If you're in the market for one, your local dollar store would be a good place to check first. You get what you pay for, but quality does not have to be first rate for melting holes in plastic.
Cheers,
Jim