Amazon is GREAT for people who don't have access to stores locally that sell breeches/riding gear (for English type gear, I'd have to drive at minimum an hour to try on pants)
I've gotten saddle burns from improper riding pants using a Wintec all purpose English saddle on a lesson horse. My knees were so burned after just an hour and 30 minutes of gentle arena riding, that I immediately went and ordered some breeches. Because I trail ride a lot and am not in an arena anymore, I don't like spending a lot of money on riding pants that can get picked easily from bushes, etc. So I got TuffRider Starter women's pull on breeches.
They have knee patches of course and no seat, but I also currently ride in a synthetic saddle that has a suede style seat so they're unneeded. I rode for 4.5 hours yesterday with a lot of trotting and posting and my knees feel absolutely fine today. These are also cheap at 28 dollars a pair on Amazon. So far I wear mine nearly every day (have 2 other pairs now), and after 8 months just now they're showing wear around the seams which if you know how to stitch isn't a problem. Knee pads are still fine even though I'm riding in a denim feeling synthetic saddle that causes more friction against them. I wouldn't recommend them for show, they're simply knock around the farm and riding pants but they get the job done and are easy to take care of. Not to mention they're extremely comfortable.