I bought the pair of calipers from "Rockauto" in the USA when our dollar still bought just over $1 US, so they were pretty cheap. . . about $225 AUD including delivery for the pair at the time.
Completely reconditioned with new pistons, seals, guide pins, hardware , etc. & a new spring clip for the pads too.
I dug out the receipt for them, they are "semi-loaded" calipers for a '1989 Mazda RX-7 1.3L R2 Turbocharged'
Centric part #CEC141.45035 & CEC141.45036 for the right & left caliper respectively.
That's exactly what I have, but there's heaps of other options on the Rockauto website for the same model year. . . loaded, semi-loaded, loaded calipers & also from a range of different suppliers.
It's all on here. . .
https://www.rockauto.com/. . . if you open Mazda, 1989, RX-7, 1.3L R2 Turbocharged, Brake/Wheel Hub, then Caliper. . . you'll get the whole list of options.
The same pair I bought would cost about $350 AUD delivered these days, if delivery is still about the same.
Don't know how that compares with the same spec from Australia at the moment, if you can find recoed ones here.
It was cheaper & less hassle for me at the time than buying second hand & rekitting the calipers, that much I'm sure of!
Cheers, Jason.