Holgar, no offense but I think your working for free

Hopefully yours is not a closed end estimate.
meaning it can't - will not go above said estimate. Mine aren't

I just got a 68 Charger in and Ted Stephens dropped of 2 quarters, 1 trunk floor with both dropoffs , 2 valance end caps,decklid and 1 fender and it was over $3k in parts alone

then the time fitting repop parts is a job in itself. I spent the better part of the afternoon doing nothing but installing wheel lip mouldings on a 1970 Cuda.

Then diag time to find out 2 wires were crossed in the new dash harness causing an inop wiper motor. it adds up,,,,,faster then one might think