mastering speakers

my students some times record demos for class review, auditions etc and i usually do the mixing. nothing fancy, I use karaoke pre-recorded songs and I add their voice on top.

I am looking into some new mastering speakers. I went to a couple of shops to hear the new B&W 802Ds but neither shop had them hooked up so I have been invited to go back when they are hooked up. I am also looking at the ATCs and the PMCs. We currently have ALON I vs with a Bryston 4B amplifier and a Benchmark DAC-1 head end.

Need some advice on some budget speakers to use for mastering (not mixing). Is there anything that could be recommended in the 500.00 to 2000.00 range? Audiophile speakers perhaps?