£10k for a Mk1?! That's a lot of money when you see the prices of Mk2s. You didn't mention the FMIC, Ti exhaust etc!! In that case, yes, it was unrealistic, but Paul (Whiffin) found me a 94 car, with 100k Kms, 19s, kit and exhaust and that went for £5.5k, so around £6-6.5k otr. I wouldn't pay £10k for a Mk1, but if you really want it and it works out cheaper in terms of mods, then it might make sense.
Btw, not a one-off as the one for £14k on Autotrader is also a manual - It's in this month's Jap Performance.