Screw a new house. This is the better investment.
You see them go for insane sums of money at auctions several times a year. Certain classic Ferraris these days can easily cost well over $25 million, and yet a brand new California T will "only" cost you just over $202k. Not all new Ferraris today will dramatically increase in value, but one in particular is already doing that at a rapid pace, the 458 Speciale. Considered the last hurrah of the mid-engined naturally aspirated V8 Ferrari, the 458 Speciale originally carried a sticker price of about $288k. Do a quick search and you'll see that's no longer the case.
The DuPont Registry has several 458 Speciales for sale, the cheapest for $389,900 and the most expensive for $439,900. So in just over one year alone this sucker has increased by at least $100k in value. Does the average home have that kind of surge? Not at that rate, generally speaking. Point being is that if you can afford a $300k home, perhaps you ought to look into buying a Ferrari instead, presumably the more extreme version of the 488 GTB whenever it launches. Just something to ponder.