I started pretty broke too, and got mine at a bait shop. It was two cups of about 2 dozen worms apiece for around $7 total. Worms are rather pricey to get a lot of them (it's about 1,000 red wigglers in a pound), but they can reproduce pretty quickly under good conditions. How quickly? Bentley over at RWC decided to find out. It's pure theorycraft, not practical counting, but it's a bit of an eye opener.

http://www.redwormcomposting.com/general-questions/will-a-red-worm-population-double-in-3-months/

Do you have a compost bin outdoors or know anyone who does? Dig around in one and see if there are any red worms in it. Or start a bin and wait, they often show up on their own.

Yup,that's what I was thinking,you can even lay boards or a few layers of cardboard down and keep it damp to attract worms. For a cheap bin that produces lots of worms,search posts by "mendopete". He is operating on a shoestring and producing tons of worms. Heck,I bet he would give you a big hand full just for stopping by. Even if you don't have room for his method,you will realize worms don't require elaborate suroundings and pampering.