For the past year, I have been using the TC Electronic Nova System. I had the G-Major for a few years prior. But when I heard the Nova, I thought the effects were of the same quality. So I did away with my rack. I also use it in conjunction with my 5150 III 50 watt (LOVE that head!!!). Added bonus: You can use the Nova, via MIDI, to change channels on your amp with your preset changes.
I think you can find them used for around the $250-$325 range. Or you can find them new for about $375-$425.
I hope this helps!