Dovers baby pads , there on sale right now for 9.99$
Usually the store brand (example: SmartPak Equine, Dover Saddlery, etc.)
In England there is a place called Robinson equestrian it’s an online store to . There saddle pads start at £6 or $8
Smartpak has awesome saddle pads for like $16! I get mine embroidered because the cost is so low, why not! I have a few of them and they’re all great. Highly recommended!