If it sounds too good to be true then normally it is !!!
Sceptical as i cant see a picture of the boat, the description is wrong and if it is a 4.8 ribcraft its well over engined for the transom, if i were selling a boat i'd make sure i had at least got the description correct in the add.
Saying that if the hull, tubes and trailer are mint then it would be a good buy just for these bits, but a 9 year old boat isn't going to be mint unless its been well loved ! and remember having had that heavy 75 hanging on the back its probably nakered the transom just a bit too.
In my experience knowing what i know now id be weary of a 9 year old engine unless of course you know its complete history, like me you could end up spending a lot of money chasing problems