Out of interest, what would you charge for a straight scan with no retouching ? Is that the $75 price ?
Actually I would never deliver something straight out of the scanner. No matter how careful you are there are things that need to be fixed, from scratches in the film to crimp marks from Refrema processing on sheet film, to embedded dirt in the emulsion or a bubble or two from the mounting fluid. I don't want anyone getting my scans to have to find junk in the scans. That price is more if you're getting multiple scans.
One of the thing that always bothered me were scanning places that charged by the megabyte, which, of course is double for 16 bit per channel and after I had been scanning for a few months, I really understood what a crock that policy was. First of all, the scanning time is exactly the same for 8 bit as it is for 16 bit. The scanner always scans in 16 bit per channel and if you ask for an 8 bit scan, the software just converts it on saving.
The other thing that most people don't know about drum scanners is how they operate in terms of resolution. The resolution is governed by an aperture in front of the lens combined with how fast the drum spins in front of that lens. The scanner I use has the smallest aperture of 3.175 microns (times 8000 = 1 inch) and then the next aperture is 6.3 microns or 4000 ppi, or more appropriately samples per inch, so the two highest hardware resolutions are 8000 and 4000. There's nothing in between. The next step down is 2667 ppi and then 2000, 1600, 1100, 1000, 800 and on down. Those lower hardware resolutions are really legacy from prepress scanning when it was much faster to get it right in the scanner and Photoshop version 1 and 2 were very slow. So for fine art scans, we really only need to be concerned with the top three resolutions and for most scans 4000 is more than adequate.
There are some limitations with workarounds when necessary. The scanning software only runs on Mac OS 9.2.2, y'know from around 1999 or so, so if you need an 8000 ppi scan from a 6x7 cm piece of film and you want 16 bits, it has to be done in two scans due to the 2GB file size limit in the legacy OS.
I don't actively pursue scanning jobs but will do them when they come my way. I bought the first scanner to scan my own film and it paid for itself in four months doing scans for a commercial client after they learned I had it. (Same thing with my first large format Epson) I'm still scanning deserving frames from fifty years of shooting and for as long as the scanner keeps working and parts and service are available.
I don't publish a scanning price list but prefer to have a conversation about exactly what's needed and how best to deliver that. Plus, my own retouching and color correcting skills are well beyond any commercial scanning lab and have often (and will still do) done test scans for free especially if someone has never seen what a good drum scan can look like.
Getting back to the hardware. Something that is not talked about much is scanner hardware resolution. Well, it IS talked about but there's a lot of misinformation there. I'm going to use one brand as an example. You'll often seen drum scans referred to as "Tango" scans, which really refers to the Linotype Hell Tango vertical drum scanner. Tango's, and other Hell models as well, have a minimum aperture of 10 microns. That means the hardware resolution is limited to a hard 2540. Ten microns times 2540 = 1 inch. They claim over 11000 dpi but it's a sleight of hand. It can only be 2540 on one axis but they slow the drum and and lead screw that moves the drum or the lens down to make smaller increments, so you get higher res in the opposing axis. The problem you see on those scans, especially high res from 35mm film with diagonal lines is that you get visible stair-stepping in those scans. Of course Tango operators do not want you to know about this. You could see this in plain view on all of the largest prints that were on display at Mountain Light in Bishop before they closed after Galen died.
It's late. Enough about scanning for the night.