I'm finishing reading the GURPS Discworld RPG and noticed an "expensive" warhorse is twice the price of a draft horse; compare e.g. 3-7x in OD&D, 8x in D&D 5e, etc.

I know J M Davidson's "Universal Price List" has seen broad use (I hope it's still appreciated these days). It puts a warhorse at 46x the price of a draft horse.