I think its a good price, I think the engine should serve you well for many more years, if its fine now. The boat is basic, as it came from mac, doesn't have any add on's like gps, depth, radio's, at least that's how its listed.
The engine controls for that 8hp are at the console, that's worth its weight in gold. electric starter on that 8hp, worth its weight in gold also. Sails look ok still all stiff and new like. trailer looks ok as far as I can see. 11 thousand sounds like a good deal, it has bottom paint so I would really check the boat out really good for signs of corrosion, the boat may not have been used much, but if it sat in a slip its whole life (clue bottom paint) I would go over the moving parts really well. check under floor boards for water and or damage. The 8hp motor would not be good for a dinghy motor, its heavy and a long shaft, but should work well with the mac, it has good resale value with the e start and controls. But it is a 2 smoker. Wouldnt be good for a john boat or small fishing boat, but keel sailers would kill for it as their main engine.
Boat looks really clean, owner took really good care of it, or didn't use it much, or both. It also has sail slugs already on the main sail, big plus, dont see a jib???
I would, like you said, just use the motor that came with it for awhile, get used to the boat. From what it looks like and what it comes with I think you scored.
when you are ready for the big motor let me know Ill give you some advice based on what you are looking for, not what I have.
Mike