As someone who worked in professional photo labs for years, I would want to make sure that the machines being used were dip and dunk, not roller transport, as there is less likelihood of anything coming in contact with the film during processing with the former. I'd want to know that the chemistry was well maintained and tested, and that test strips were run frequently, and then plotted. Most places won't mention any of that in their adds (Ilford, which uses Refrema dip and dunk machines (which are GOOD) being an exception), but I don't think it is inappropriate to ask. Asking to see the chemistry plots of a local lab is not, as far as I'm concerned, out of bounds. If you do, you want things within the dotted red lines, well within and without wild ups and downs being preferable.
These is probably the anal instincts of someone who processes his own black and white and who for years worked in the labs that processed his E-6 and C-41 color film. Nonetheless, the consequences of a film processor not chemically in control can be real and devastating. Color shifts can be permanent and irrecoverable through filtration because the shifts will not necessarily be the same on every color layer.
Blah blah. Sorry for the lecture. But do make sure that inexpensive processing isn't cutting corners in monitoring chemistry or cleaning machines.
