+1 on ceiling first.
For about the price you were quoted for R38 you could spray foam 3" @ R7/in. Not as high an R value but a better seal and no vapor barrier needed. There are several vendors that sell kits as large as 600bf for about $1.00 bf.
Assuming that you do not want to pull the ceiling drywall down and that the builder did not install a vapor barrier (he should have to keep fumes from entering the house) - If you put down batts or blown in, I woulds lay down plastic VB first, wrapping it over the joists, taping any joints, etc and make sure that soffit vents are not closed off with the kits they sell for that. Also pay attention to electrical boxes, inset lights, etc to make sure that they are properly treated (most will probably want insulation kept clear).
Retired - when every day is Saturday (unless it's Sunday).