Pete I don’t know what book you are looking but it pays 20 hours to O/H the carbs if you do it right. I lost count over 3 years ago but up to that point I had done over 300 sets
I based it on what time it takes me to remove, clean, replace parts and reinstall on a Valkyrie. I do mine and close friends (as a favor), I do not do commercial work anymore. As for a book, I do not and did not use one, just actual time, parts and shop material cost.
As for dealers in the area they charge $650 for a chemical carb clean and do not tell the customer they do not disassemble. I do not know what they charge for a removal, disassemble and clean.
Your charge of $750 is very close to the $400 to 600 labor and $150 to $200 for new o rings, float bowl gaskets and float valves parts of my estimate. So it seems we are actually in agreement?
I have not done 300+ Valkyries but I have been working on Goldwings and Valkyries ever since they came out 1975 and 1997. And I hot-rodded the first Goldwing in this area in 1977 with Honda 600 pistons and special one off cams, opened up the carbs and intake to compliment the cams and increased displacement. So I am no novice, as I have done many, not just 1 or 2.
I answered his question based on my actual times in accomplishing what he ask for. It is what it is!