Yeah, roasters are pricey. If you want more control over your roast, but don't want to spend tons of cash, I would honestly recommend heat gun + dog bowl. It's what I do, and I'm really happy with my setup! There's a learning curve, but you really do have a lot more control and it's DIRT CHEAP.

I use this Porter Cable heat gun and this stainless steel bowl (with the non-slip silicone). Works like a charm!

Edit: Here's an awesome heat gun + dog bowl guide by Michael Lloyd.