My friend and I have just spent the last month striping and prepping an rb26 to fit in to a VL and he blew 6 grand on the short block. But it is built for around 800-900Hp. cp pistons, Jun rods, machined crank collar and N1 pumps etc.
And that was with us building it. So if you are getting someone else to build it I would put aside 9 grand for a strong engine.
Cheers,
Boz