'93 Trek 820 Antelope - Replace?
You don't have to spend $2K on a bike that will be faster, lighter, easier to ride and generally better than your 25 year old bike. (I'm assuming the US here as you used mentioned dollars).

That said, if the old bike only needs minimal maintenance that will not be expensive to do so, get it into a satisfactory condition and ride it for a few months. If you stick with it, then consider a new bike.

If you are not riding proper mountain bike trails, a hybrid bike with no suspension will be perfectly adequate.