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.
I have done repair work for many years. Thousands of repairs. My go-to tool for general repair/replacement has been pc1500hd (variable heat). You won't regret it.
https://www.amazon.com/PORTER-CABLE-PC1500HG-1500-Watt-Heat-Gun/dp/B004Q04X44
I had a heat gun on hand. I've heard that a hair dryer will work, but can't vouch for the effectiveness. If you want to get a heat gun, I have this one, and it worked very well.