https://www.avalancheoutdoorsupply.com/collections/womens-leggings

They have fleece leggings with pockets for under $50 but I’d say you’d probably have to replace them every few years.

Leggings are hard to find BIFL. I think the only leggings I know that would be BIFL were the original made in Canada Lululemon leggings which were over $100 years ago.