It's a scam. Do a google search on "If it's still available kindly get back to me with pictures & a detailed explanation of it's present state" and you'll see hundreds of hits with the exact same wording... all scams.
If they are serious, have them send the payment via western union. You don't even have to give them your name for that, an alias will do. All they need is a password to attach to the funds when they western union your money. All you need is that password (and the $ amount I think) for you to get the money from western union.
Here are some other tip offs that it's a scam:
"Arcade Cabinet Donkey Kong Jr" is probabaly the exact wording you had in the title of your ad, is it not? That's a hint of an automated or quick cut and past response. Probabaly scripted.
there are TWO spaces after the "Jr" too, another sign of a poorly programed script.
"know the best possible amount you are willing to sell for" is another hint of a scam. The scammers try to entice people by offering more than what the seller is asking, or by offering the "top amount" that the seller is asking for.
another tip off is that you're selling a large item that would have to be truck frieght shipped. The next step for them is to send you a message stating that they are ok with the price, but someone stateside will be sending a bank check for $4,000. They'll tell you to cash it and even have the bank verify the check, then send them the $3,825 and they will arraigne for the item to be picked up. They will never make these arraingements though you will be out $3,825 after the bank calls you and tells you the main branch declared the check a phoney....
BTW: it takes about 15 - 25 days for a check to fully clear the banking system, YES even a money order, cashier's check, or bank check.
Please don't fall for this scam...
Mike B