am i paying to much for race short block?

Some other things
Most of your JE domes on a 500 motor are big crompretion in 74cc heads.
Also ask about the crank caps-mainly about if the block has studs for the cap.
Is the bolk filled?
Did they block your oil pickup?
Did they put in oil restictor to the heads.
What cam bearing are in it?
The price seems pritty good but you don't want a motor that is built to need parts you dont have. I.E. Side oiler- Rollercam.