I have 3 pair of HR Farm brand on amazon...I love them and they're around $40. I also have several that are 2-3 times more (Dover and Kerrirs) and I honestly like the Amazon ones better.

HR Farm Horse Riding Women's Knee Patched Breeches https://smile.amazon.com/dp/B07W6SJNPK/ref=cm_sw_r_awdo_X3TQ3TQ515C4NFAG11XJ?psc=1