Years ago I bought a Chinese reflow oven from Ebay. I think all cheaper versions contain a quartz-lamp and some type of temerature controller. I found that it was essentially impossible to achieve a correct reflow temperature curve, with the result that many boards simply were burnt when they came out (really burnt, like black...).
Currently, I simply hand-solder my prototype boards and have my factory reflow larger orders. I suppose, if one has, say, 10 boards that need to be assembled, a DIY approach with a toaster may work.
I sold my reflow oven and has not missed it since...