I am not a seamster (seamstress?). I have a parka that I did not pay a lot for but I really like it. After about 20 years of use, I blew out a seam on it. I could’ve tossed it but they don’t make ‘em anymore and it’s still in otherwise pretty good shape. I took it to a local tailor shop and they did a very nice job of fixing it for a very reasonable price.
You have Patagonia snowdrifter bibs (which I looked up on line) worth about 350 bucks. Crotches are not easy to fix for the average person (don’t even ask how I know this!). I strongly recommend finding a local tailor to fix these right. You won’t regret not having tape in your crotch! Just my opinion. Good luck!