So what do you really need for sous-vide?
You need a vac-pack system. There are ways to get by without one, but they're sub-optimal at best. Costco.com is dumping the old "flat" model FoodSaver for half price right now.
You need a blowtorch to finish your food, because cooking stuff in a vac-bag doesn't produce any browning or caramelization, and you're missing out on flavor. Any blowtorch is fine, as long as you're not using the citronella propane.
You need a precisely temperature-controlled water bath. Now if you don't want to spend a grand or more on an immersion circulator, there are some relatively economical alternatives:
There is, of course, the ghetto-tastic solutions of doing sous-vide in a pot in your oven. The temperature control is pretty sloppy then, though.
There is basic crock-pot sous-vide. The temperature control is consistent, but pretty inflexible. Low, High and warm in most cases, and you're going to have to measure those temperatures.
The real winner is rice-cooker sous-vide with a good precise thermal controller. You can just go out and buy a controller from Auber Instruments and build your own, or you can buy a whole kit (including the modified commerical rice cooker) from Fresh Meals Solutions. The inventively named "Combo #1" is a reasonably-priced system featuring an interesting cooker that includes a ceramic pot insert for cooking stews and soups in a temperature-controlled environment (if you don't have the equipment to vac-pack liquids).