I say go it, because if you do something a little dumb now and then it makes the smart decisions you make look better by comparison. On the other hand, this is jinjuku we're talking about, and he makes me look adventurous, so it seems.
A $175K 458 is possible, but that would be a pretty cheap one, from my glance at the market. More likely you'll find one worthy closer to $200-225K. If you only keep it for six months you may not need to do any maintenance. Even a $175K 458 may have less than 20K miles, so the chance of it needing major maintenance is small - unless it was tracked. If it was tracked you're possibly screwed, because everything on a Ferrari is very expensive, and only the dealer has access to the documentation and training. Before you buy one you really need a pre-purchase inspection. I'd figure something like $500-1000 just for that. Parts cost example - scrape one of those wheels by parking using the braille method? In the $6K range each for a new one. Flawless used are like $3K, if you can find one that matches. If the double-clutch transmission ends up needing work because it was beat on the track, good luck with that. I've only known one Ferrari owner personally, and he bought it to track it. (He let me drive it on the street, and I totally fell in love with it. I should also mention that you should be comfortable with a lot of attention if you want one. I told the owner I felt like I was Jennifer Lopez naked, for all the attention I got, driving around Sarasota, CA, which is one of the richest places in the US. This was in about 2007.)
Then there are other considerations. Like insurance. Mainline insurance companies may be unwilling to insure it. Specialty insurance is surprisingly pricey. And registration, property tax, and sales tax. Kentucky (I think jinjuku said in lived in KY) has cheap registration, but a 6% sales tax, which I'm guessing he'd have to pay at registration time. $200K x 6% = $12K.
The other thing I noticed in my 458 market glance, there are a lot of them on the market. And I just looked at autotrader.com, which is not exactly a hot Ferrari listing service. I think every 458 in Scottsdale must be for sale right now. So when you're ready to sell it might take a while to make a deal, like months.
Nah, I don't think I'd do it.