Rock Auto has calipers for $40 each, you masochist.
1973 BMW 2002 2.0L L4 Caliper | RockAuto
WWW.ROCKAUTO.COM
RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.
And one Uro parts MC for $87.
https://www.rockauto.com/en/catalog/bmw,1973,2002,2.0l+l4,1010754,brake+&+wheel+hub,master+cylinder,1836