Lets just say as usual Hardcore is wide of the mark!!!!!!
If you actually check the link given.... you will see that one V5 is a 110T the other is a 50T
"Xilinx Virtex-5 XC5VLX110T XC5VLX50T"
You can get a double hashing core into the XC5VLX110T.
I have just finished research which gets the hashing rate upto 370MH/s per chip at a little over 10W per chip.(why?, because i'm bored)
As for the XC5VLX50T good luck with getting any decent hash rate out of that!!!!, because you would have to go with a nested core and not an unrolled one.
So actually if you buy that board, we can see from here:
http://tpbitcalc.appspot.com/That at 200Mh/s which is a public bit file, you would need about 85 days to recover the cost, and since Avalon and BFL(most probably)
will have dumped a shit load of ASICS in the next 3 months, it is unlikely you would see any decent return.
I myself have indeed been buying up FPGA's at stupid prices, but that is for a project on litecoin, but first I will mine bitcoin to recover the cost of the XC5VLX110T's.