Unless you arer getting some good aftermarket heads and matching intake included for that price, I think it`s a little high.
A 350 long block with stock cast iron heads and cast flat top pistons can be had for 900.00 to 1500.00 depending on where and how much you shop around.
Obviously the price will go up depending on what upgrades you decide to make, such as... Forged pistons,roller rockers,roller cam/lifters,aftermaket heads,timing set,oil pan size/style/volume,and what type of machine work you opt for,ie.(balancing,decking,boring,milling,polishing,port matching,ect.