Given those budget constraints, I would go with the best amp I could get & use a passive. There are several passives to pick from in the $150.00 range or you might even consider attenuators. This is taking into consideration the other components in your system will not change for the time being. I also recommend only changing one piece at a time, so you can get used to it & see how it fits in with your overall plan.
If you haven't already done so, try & tune your room as best you can to realize the full potential of your gear.
Good luck!
If you haven't already done so, try & tune your room as best you can to realize the full potential of your gear.
Good luck!