Just keep in mind that spending less in the short term could well end up costing you more over time. Of course, you can't spend $$ you don't have.
The Red Box is a speaker simulator. About the size of a stompbox, it's a great sounding substitute for a miked speaker cab. I scored mine off evilBay for ~ $70.
You'd run the amp into the hotplate to provide a load to the amp. You'd then run the hotplate's line out to the red box to simulate the miked speaker cab.
In this application, a Weber Load Dump (they come in 25/50/100W models) might provide a more cost effective alternative since you can score a 50W WLD for $75.