At this price point, hard to pull off. If it’s docked, it’s basically just a PC though. Look at r/BuildAPC or PCPartPickers Build guides for some idea, if you’re willing to try to build one yourself. Or just buy a gaming rig.

Yes, but I’ve never found them cheaper than buying on Steam directly. All third party sites always seem to have a markup on them.

Can’t you just do a factory reset?