I learned never to touch a 335 that is out of warranty. A lot of people say they rarely have problems others say its like hell for them. So I came to the conclusion it's a hit or miss, you either get one that's tough to maintain or you get a good one. Seeing that that one has very low miles is nice, but that means you're going to be the one that has to do all the main repairs for it (waste gasket, water pump, etc..I'm not sure exactly all the problems for it but its a long list) Kind of like how our n52 have the valve cover gasket, oil housing gasket, oil pan leak, water pump that every n52 has to get fixed..so imagine all that plus more for the 335.
I'm not saying don't get it because that honestly sounds like a great deal. Usually with that low miles they go for a tad more (I was looking into 335's a couple weeks ago) but if you're pockets are deep enough for the repairs by all means go for it and have a blast! You won't regret the fun factor that's for sure. And since the miles are still low you can put a couple hundred aside for the repairs when they hit
I've kind of accepted my 330 is "slow" (by today's standards..the average car is getting faster and faster) and I'm probably going to keep this car for a long while so I might as well make it a looker and maybe have some minor performance upgrades.
Anyways, good luck on your decision!!