I don't know what you consider low budget, but I just priced the getrags at the first site I found, and the 3.92 cost 1150, while a 3.73 cost 2500, the 3.06 cost 1350. They showed these prices as reduced. Again, this was just the first site I found. So to me, this isn't low cost, but I'm tight fisted with my $$$. I don't know what kind of performance increase you'd get for the SRT diff's but I would think your 0-60 would increase some without eating into your gas mileage too badly. I've thought about doing a similar upgrade as well. If you can get it from a junkyard or someone selling their old parts, I'd say it would have to be way cheaper than buying a new getrag. But I am no expert by any means, so if these guys say it's not worth it, then maybe we should take their word for it.