I get paid per mile on mine for work too and I was reluctant to put the miles on at first and as
@PT82 said, I had considered buying a cheap run around.
After consideration I got more money per mile for the 2L engine and I'd enjoy it every single day so I stuck it out in the GTI.
I've put nearly 20,000 miles on it since but I enjoy every minute of it and net about €6k per year in mileage to counteract the devaluation of the car.
Now that €6K excludes the additional cost of petrol, tyres and more frequent servicing but I'd say I'm clearing around €2.5k profit maybe....