Tuffa suede half chaps. Dont know if that is very cheap as they are leather which costs more than fabric. They go shiny on the inside after years of use. But mine are 11 years old.
I have Shires cheapy suede ones. They've come out well after several goes in the washing machine believe it or not. Nice and stretchy and only about £20 IIRC.
Bridleway fake-suede half-chaps from local tack shop have soo far out-lived the decathlon/Brogini ones (and pricey long leather boots - but thats another thread ). Fully washable, fastenings have survived daily use since June - for £23 super value