Out of curiosity, I called the Acura dealer to find out how much they would charge for a valve clearance adjustment:
The parts cost is for four rubber gaskets that they always replace as a matter of course whenever they remove the head covers. When I removed mine the rubber gaskets were in fine shape so there was no need to replace them (this is in accordance with the service manual that says you don't have to). My costs:
So, even disregarding the cost of the new gaskets, I still came out ahead $20 on this job. Of course, I'm counting my time as $0 and I can use all the tools again, so I'm really comparing apples and oranges here. The only tool that isn't generic is the special Acura tool for adjusting the valve set screws, which was $75.
The satisfaction of having successfully completed the job myself is worth more than $20.