Wait until you move.
Remember to get a insurance quote first some areas can be a pain for insurance.
Many have mentioned fuel costs but tbh mine running closed loop and coilpack can easily see 30 plus mpg on the run but once on boost they like a drink and it's super unleaded.

It's very tight with 2 child seats and a adult and remember to cover seats in some kind of padding as the child seats will damage the seats I have proof of that......

Imo service history is not too much of an issue who needs to see if it's had 4 sets of lowering springs and 22 different types of dump valves.
Check oil is clean
Overall cleanliness
Mot's match the mileage
vin numbers not had any welding around it.
vin tag on slam is in place.
2wd's if not rebuilt will have piston slap when cold this is normal and lessens once hot.
Accident damage are the panels genuine ie wings etc.
Do all the panels and front end line up? One on eBay atm looks like it's had a front impact...
Are the tyres a good make ? This will prove to you the owner cares about the car.
Buy from an enthusiastic owner not a garage unless it's a specific RS dealer like KGM.

Do your homework check online for mot history and hpi and cat cars.

Paul