a car like that in the states with no drivetrain, and being a 73 coupe is worth about $500-800 here
$7500 usd is what I'd expect to pay for that car if it was in show worthy condition....and honestly even that price is a couple or three too high.
However, I can't value something that far overseas, so you're going to have to try and comparison shop to see if that price is fair.
Think of the car as a building block....your main concern is going to be rust. Look over the car extremely careful..you want it to be as rust free as possible, because getting sheetmetal replacement parts will be next to impossible over there.
If it's rust free, the rest of the car can be customized...you can take it to an upholstery shop and have them make a custom interior for it, or you can do it yourself, ...make your own carpet, then add some front seats in it from a donor car over there and fabricate your own seat brackets etc.
The drivetrain though is the most difficult part. The original v8 that that car had won't do more than 13 mpg's or so on the streets.
My personal suggestion is a newer v8 then from say a newer fuel injected mustang, if those are available there. If not, well you're gonna have to be creative.
Keep in mind that that car is heavy, so in your quest for fuel mileage, if you stick too small an engine in it, and it's underpowered, it'll hurt your fuel economy too.
you say that the imports are available over there, what about toyota or ford or chevy trucks? A good modern v6 engine from a modern truck with the tranny would get good fuel mileage and would be powerful enough for the body.