Thursday's dilemma

Learned today that my neighbor, the awesomely-named Dallas, is selling his blue 2002 Honda moped for a meager $500. I have coveted this scooter for years. What's wrong with it, you ask? Nothing ! He simply doesn't want to store it for another winter. My little brother and I are thinking of going halvsies on it -- $250 each and splitting the time we use it. At first I thought I was weakly submitting to my occasional materialist inclination, but then I realized that riding a moped is, in fact, a means to save the world. Think about it: 80-100 miles per gallon; filling up the tank for an insignificant $1.50; and riding my way to work for as long into the winter as I can withstand the cold. Al Gore does tell us to drive a low-emmission vehicle. My Saab gets pretty bad gas mileage and, no matter where I find an apartment, I'm going to have to drive to work. It's also a sound financial investment -- in the long run, I'd probably save money.

So.... do I go for it? I did some internet research; here are the pros/cons:
(+) The gas mileage, almost end of story.
(+) As far as scooters go, Honda's are the best. Way more reliable than Vespas.
(+) This particular scooter is in great condition -- ready to go today.
(+) Everything for a moped is cheaper: gas, insurance, registration...
(+) Moped riders don't need a motorcycle license to operate in Massachusetts -- ie one hurdle overcome.
(+) $500 is the best price I'd get. Ever.
(+) I rode horses all through the winter growing up, I think I could handle a scooter for most months of the year.
(+) It's awesome, obviously.
(-) I don't exactly have $500. Or $250. Actually, I don't have anything close to it. Meaning: I'd have to owe my brother my half of the deal, paying it off in increments from my AmeriCorps stipend, which we all know isn't exactly putting out Goldman-level salaries. I've already spent the past six weeks paying off my credit card bill from this summer's travels, and everyone says don't get into debt. At the same time, wouldn't it be a money-saver in the long run?
(-) No, I couldn't really ride it all year long, meaning that storage is an issue, December - March. Zu basement an option?
(-) A potential source of conflict between me and my brother. Obviously we're both going to want it all the time. But I think we could be mature about it.
(-) Insurance, registration, et al is always a hassel, and I already have to manage my car's upkeep.
(-) Getting it down to the Pioneer Valley is also a problem, requiring a U-Haul, which would require a 'relocation' grant from AmeriCorps. But I'm getting that anyway, I think.

Any of you all have an opinion? I'm taking it for a run around the neighborhood tomorrow...