In case you want to try it, rebuilding the calipers is fairly easy. I rebuilt them with the OEM kit from the dealer. I used some rubber hose on a screw driver and plugged it into the union nut to prevent the union nut from leaking the brake fluid when caliper is removed; so, I didn't have to run out of fluid and bleed the master cylinder. To push the pistons out, I just tapped on the brake pedal -- no compressed air was needed. You clean everything and lube with brake fluid and also glycol grease if provided in the kit. Lube the bushings with brake grease.
The only somewhat tricky part is installing the dust boot. Just make sure that you don't forget the old snap ring inside and install the new boot and snap ring properly -- with the correct orientation of the boot and snapping things into correct grooves.
1985 Toyota Corolla LE, 4A-LC engine, ~ 257,000 M
Toyota (by ExxonMobil) SN/GF-5 0W-20 Synthetic
Toyota 90915-YZZF2 filter, 90430-12031 drain gasket