I would call and ask Ray directly for the most accurate pricing information. But most people will charge a "service call" fee to get to your house, especially if you are 45 minutes or an hour away or more. Time, gas and tolls are big money and nobody can afford to eat that.
You mentioned 5-6 games that need work. Some of the work can take some time to diagnose and fix like missing sounds, dmd lines, opto problems, etc. Sounds like several hours work at least plus parts. The parts could well include replacement boards, a DMD, optos, etc. I don't guess that will be cheap. I'd be amazed if you got away with less than a $500 bill. Could easily go $1000, and maybe more if your boards can't be repaired on-site. It is what it is unfortunately. But Ray is a good guy in the service world. He can fix it right the first time. There's not many others I would trust who are as proficient as Ray and who carry as many replacement parts with them as he does.