I bought an EBII Fairmont (not Ghia) last week.
Could only find out a little of the history, but it is showing 104000kms on the odometer, and general condition seems to be consistent with this.
Price was $5,500. Will need new tyres in the next 5,000...the discs need a machine (I can feel inconsistent wear - but roadworthy was ok)...and I think the aircon needs gas. Apart from that, all else seems OK and the vehicle is in lovely condition.
Check out www.redbook.com.au
for approximate market values. I would think between $3,000 and $5,000 for these, so you might find that you are paying at about the top of the range. Of course, that's to be expected if the vehicle is an excellent example. K's do seem high though (for the price)...have you made an offer? I would probably ask them if they'd take $4,500.
In the end though, it's your choice. If you absolutely love the car, then I would think that $5,000 is a reasonable price to pay for the satisfaction.