I got a NEW starter from 'dbelectrical' on eBay for about $120 shipped. It's been perfect for 8 months and counting- it cranks a lot faster than my old one ever did. I took a chance because I didn't trust a big-box rebuild, and it seems to have paid off.
2 cans break cleaner and a rebuilt kit and any shop with a spot welder you can rebuild them your self, usually a good tear down and rebuild solves most problems, cleaning the brush guides and honing the brushes flat again and cleaning the commutater with the right undercut of the mica, clean lubricate the gears and bendex.
As for electrical take apart and wire brush and clean, re-assemble then cover in dialectic grease, and all the signal lines I replaced with 10awg marine rated wire, crimped and soldered then heat shrunk with the double walled glued heat shrink. takes allot of work but the next time you'll work on the starting system will be ruffely never.
The problem is getting decent parts. At work I rebuilt everything from the 30+ lb. 24V Delco (Cummins 335) starters on down, but nowdays looking all over the net all I could find for my Ford was DB Electric and a couple others that appeared to have nothing but "overseas" brushes, brgs, solenoids, etc. I gave up, went to the local auto/electric and he rebuilt mine with top quality components in a couple hours for only $104.
probably true. also the denso starter is a monster. mine would keep starting my truck even when my batteries were long past the point when I should have replaced them. Maybe it's just set up for a lower voltage.