I wouldn’t say it‘s too unreasonable. It looks in nice condition as well.
Ideally the seller could add some more pictures (showing a shot of the screen working with the game on for a start) and also a few shots of the rear and inside the machine. Writing a description more than 6 words wouldn’t go amiss either, saves potentially being messaged the same questions from potential buyers. If you are expecting someone to part with over £2k, then at least spend a bit of time describing the machine in a bit more detail.
Sprint 2 does pop up now and then, usually closer to £800–£1200 depending on condition. Unless it’s super mint or has some rare history behind it, £2k feels more like an optimistic seller than real market value.