For me it has to be my mint USA MS NGH cart.
cost me $2,174 Canadian (about 1400 US)
I my only regret is that i wish the payment was payable to SNK, they need the money and I'd die to see a ms4 one day, I really enjoy the game and I play the MS series more than others. I'm not made of money , I just prefer to buy neo geo carts ,drive a rust bucket and crave a cigarette. Rather than smoke,die early ,and make a monthy CDN$400 payment for a new car thats gonna look like the one i have now in 5 years.
I do have the Mvs carts, but I have been bitten by the neo geo collecting bug, To me its for the better, I have quit smoking,I am healthier and I have a collection thats worth more than a pile of ashes and butts. I put $4 away every day in 2dollar coins ( I used to smoke a pack a day) and use that savings to buy rare carts (you'll be suprised at the amount you have/will spend on smokes in the long run).I know I was when I opened the coin door on my mvs and counted it ,,,this way when ever a cart I need comes up for sale I have the cash and dont have to break my budget.