How much to drill and helicoil head bolt threads

[sam196370]

'91 560 SEL - I have the motor out (again) - I was going to take off the heads and bring them to be rebuilt. I've read that the bolt threads in the block need to be drilled and helicoiled; I thought this would cost $500+/-. I was told that this job - JUST drilling & helicoiling the bolt holes in the block, remember I'm bringing the engine to the shop with heads removed - would be 2 days of labor or around $1,500. Is this the market price for the job? I feel like if I had the stencil I could do it in a day.
If anyone knows of someone in the tri-state area who has the stencil and might charge a more reasonable rate, I'd appreciate it if you would let me know.
Thanks