I have a 2020 Rockhopper Comp 1x...love just about everything about it. Specialized made a 2020 Rockhopper Expert that had a tapered head tube and a boost spaced rear, and it came with tubeless ready rims and a better shock and a lighter aluminum frame. I decided I REALLY like my bike but dont wanna put alot of $$$ into upgrading this one, so the Rockhopper Expert looks like a great foundation to keep long term. My plan was to buy a new one in 2021...but Specialized change the frame and the Rockhopper no longer has a tapered head tube or boost rear spacing in the lineup so a 2021 isn't going to work. Looking for a New (or slightly used) 2020 Rockhopper Expert. Dont see very many used for sale and I dont see many available online. Any thoughts on where I might look to find one? If I cant find one, I may be looking into a different bike,

Facebook groups are your best bet for a specific model or brand.

I don't know what's there for Specialized. For Salsa and Surly there is a buy/sell group and an owners group... the buy/sell group allows no posts of non-brand parts, with the maybe exception of something like an OEM wheelset. The owners group doesn't allow buy/sell postings. It seems like a good system. For MTBTandems there's a group that allows either kind of post as long as it's MTB tandem related, and that's a small enough group it seems to work ok for lack of anyone malicious enough to test the rules.

It takes some effort, but I once found a discontinued model by checking websites and calling or emailing independent dealers around the country until I found one who still had the frame I wanted in stock.

Specialized ought to have a pretty good idea of where they sent certain models of bikes to see if a shop still has one in stock. that is extremely unlikely in light of the massive, unprecedented demand for bicycles for the past year.