I have a Stargate as my first pin!
£3.25k is quite a bit, but I've never been one for super-mint stuff. Maybe if it was in tip top condition with a colour DMD... For reference I had mine for 2.5k several months ago, and I don't think the market has got that much hotter in that time.
The game is very fun. Its multi-ball heavy, and can be set up fairly challenging. The callouts IMO are great and the music is a vibe.
Normally for the money (this one may be a little too expensive to say this) Stargate is far and away the pin with the most bang for your buck IMO. It's a fairly modern game, with a DMD, modes (Including two wizard modes), three flippers, fun ramps, several different ways to play, and cool art. I can now some regularly get one or the other wizard mode in a game, and have lined them both up I think twice. Still it feels like there is more to play as getting the wizard mode is one thing, doing well and scoring super jackpots is another, and doing all that with a boosted jackpot value is another!
Maintenance wise, expect to have to rebuild the flippers. The system 3 flipper design is such they wear quickly, and when worn they don't smoothly make the right ramp. While there I really recommend changing out the coil stops from a Gottlieb system 1. It stops the flippers being able to literally catch anything by making them have a more shallow range, which makes the game much more flowy.
Apart from that, all I've had to do is adjust switches and replace rubbers. Also, the game is as heavy as ****!