One frame is 1440 samples at 48 kHz, and 1323 samples at 44.1 kHz. This explains the strangeness of there sometimes being 32 frames to a second, and sometimes 33. Supposedly, the tape heads are only guaranteed to work if cleaned 25 times, or used 1000 hours, whichever is less. The cleaning tape pretty much acts like sand paper on your heads, taking away any dirt and some of the head as well. 40-50 cleanings and the heads are gone .
Labor costs vary from area to area.
Tascam has a document on this that you maybe can request from them if you feel up to it, I'm too lazy to type in the thing. The transport has been improved over the years. For picky machines, the DTRS tape by sony and basf is an improvement. It is really important to reverse fan direction and install the filter as per my modification because you would not believe how dirty the machine can get. Even with Tascam's plastic guard, dirt accumulates in the reel clutches, under the mechanism and can contribute to head wear.