Re: Does $90 seem a little steep to re-tube the power section of a 40 watt amp?
+1 to what SRS said...Also, what amp is it? Some amps are more of a pain to service than others, so that could be adding to the Price. This is why most people buy tubes themselves, and do this stuff themselves...Tech's will Rape you in the face if given a chance, Because they can. If you don't want to do the Biasing yourself, some techs will be ok with you bringing in the tubes you wish to use and then just charging you bias the amp.
I know I certainly wouldn't pay $25 each for an Ruby tubes...Buy some JJ's, EH's, Tungsol's, etc... from Dougs Tubes, or Tube Depot, etc...it'll cost ya slightly less, and sound a **** load better.