I might start selling the .stl file on my website for folks that already have 3D printers. Probably in the $3-$5 range. The issue that folks will run into is experience. The rear cup holder is a 2 part print (not including the inserts) that totals 30+ hours. It takes quite a bit of experience to be able to print a part that long without having any warping or cracking. Took me 100's of prints and many spools of filament before I figured out the right formula. There is also the issue of the printer. I had to make huge upgrades to all of my printers to be able to continually run 30+ hour prints. Then there is the issue with support removal. If done wrong the cup holder can get damage. If you get the supports off without damage you run into the next hurdle which is the acetone bath. If done wrong you have a melted cup holder. If done right it gives the print a nice smooth glossy injected molded look. I am okay with passing the file on to folks but I want to make sure they understand they may have to go through a few prints before they get the machine and their skills dialed in. What I should do is make a youtube video of the entire process from setting up the print in slic3r, to dialing in the machine, to monitoring the long print, to platform removal, to support removal, to sanding, to acetone, to finally paint. That should ensure folks are able to create a quality print with greatly reduced issues.
That would be pretty sweet if you did. I would pay that in a second just to have another printing project. I got my ol' rep rap pretty well dialed in. You ought to look into resin casting. Like anything else it requires some experimenting to get everything to come out right, but if you are looking for production runs larger than what a few 3d printers can handle but smaller than an injection mold run, you can accomplish it easily. It will also likely cut your costs in half. I did quite well making and selling door panel brackets for my old e36 BMW a few years ago.