Those cards were pretty good. I have some rigs based on that architecture in my mining operations and they run just fine for months.
Regarding the price, 2400 since a medium-high price if we consider just the hardware, this changes if it is an already built one since it prices also the ability and time to build it.

Right now I would not buy it because:
- Next generation of GPUs will come out in a few months (probably we will have it on our farms around September)
- FPGA rumors about every GPU algorithm are getting stronger
- ASICs for many GPU algorithms are being released faster than ever

I would be happy to read different/opposite opinions and discuss about pro and cons