Could be wrong, but IIRC they were a £2k+ option when new. That's not bad pricing for the time of year to be honest. If you wait 3 or 4 months you might grab one for £650, but I've never seen them for less than that.
In fairness, it'll cost you £700 to replace your roof motor if it goes, so a hard top is not an unwise investment if you can pick one up at about that price... And have room to store it in the summer.