I've just submitted an offer for a slew of T480/T490/T14 and some Elitebooks in a "B-class" state; busted screens, malfunctioning keyboards, etc, avg price is in the $30 range. no SSDs, chargers, and save for a coupla T14s with onboard RAM, they're usually without RAM. so once completed, they should be in the $100-$150 range.

I wouldn't dwell too much on the price, whether you can have it for $200 or $300 isn't really significant, it's not like you're doing this twice a year. whatever you get now will last you for many moons, so amortized over that period that's nothing to fret about. make sure the battery/ies are OK as finding a good aftermarket replacement's gonna hurt.

T14 is obv better than T480; yeah the latter's got two batteries, but the former sips way less power while packing more power; also Ryzen options (5000-series and later only). serviceability is similar, huge cross-model/generation parts-compatibility. soldered RAM used to be an issue, but with today's prices, having 16 GB on-board (+ one slot free) can be a welcome addition. def stay away from the X1; the heft difference is insignificant but it drastically limits the upgrades and repairs you can do on your own.