That's very minor damage mate. The chassis leg has most likely only bent in at the crumple zone, about 8", quite common on all VAG platforms cars of that era. In all honesty though if you can't pull it out and weld yourself then £700 to repair sounds about right, quite good actually. I've just bought an identical one myself (albeit without the damage) and the lad selling did say they were worth more in parts sadly. You can, I believe use the crumple zone part off any polo of the same era as you see a lot of them in the scrappy. Chop it off a fair bit further back, drill out the spot welds with a spot weld drill and drop it into the repairers if you go that route.