The value of most typewriters is dependent, or should be, on its condition. That's where the discussion should start. Is the machine complete? Is it functional? Is it a fully restored (professionally) example with fresh rubber or a rusted solid barn find?

Beyond that, what's it worth to you? Do you collect typewriters, or is this likely to be the only typewriter that you'll ever buy? Does it have any historical or sentimental significance? Is the typewriter being shipped or is it local to you? If it's local, what is the typewriter market like in your area? How motivated is the seller? Does the seller know anything about typewriters - or the specific model you want to buy?

In my experience too many people overpay for typewriters, whether it's because they lack experience, get caught up in the moment, or are drawn into an effective sales pitch. There are - without any exaggeration - millions of typewriters still in existence and despite what someone trying to sell a so-called "rare" model will try and convince you, other options always come along. It's a buyer's market.

Buying typewriters is a game of patience.