I know that area, I live a couple of miles away.
Things of note: the traffic! It's close to the crossroads and it's chocka at peak times. It's near the crossroads to Nunhead, ED and Peckham so for that reason I wouldn't buy it.
It's in the "wrong side" of ED. Closer to Peckham than Lordship Lane.
Lots of buses run along that main road by the common but if you want to get the train to Central London your only options are to go to Peckham Rye station (which is horrible) or walk to East Dulwich (which often closes due to engineering works or signal failures).
But the common is good if you have a dog or kids. Some nice pubs and coffee places nearby.
I would probably take my three million elsewhere tbh.