Yes they are. I had a Music Reference RM5 mk II that I sent back for a minor mute circuit repair and got a PAS 3 to hold me over until the repair was done. When I got the MR back, I preferred the PAS much better. A modded/updated one will be far less than your budget and should be readily available on that other auction site.
If you don't go with the PAS, there are lots of other tube preamps you can consider as well.
If you don't go with the PAS, there are lots of other tube preamps you can consider as well.