I don't sell anything on ebay, but I wouldn't think it would matter, but I'd stick with the reserve.
Take my perspective as a buyer, if I see something with a reserve and it hasn't been met yet I may or may not bid on it depending on if I really want it or not. Still, I might be encouraged to place a bid even if it is below the reserve. Why? I've seen a few times where the auction ended, the buyer and seller got together and worked out a deal.
On the other hand, there could be an item that has a high minimum bid. It might actually scare me away. Versus if there isn't a high minimum, I might bid on it and then keep bidding in the heat of competition.
Some things I'm sure you know, but that I consider more important are,
1) Include a picture...as clear as you can get it.
If I can't see what it looks like, I'll never place a bid.
2) Include a listing of the game(s).
If you do have a picture, but I can't make out what the name of the games are (especially if there a lot) and there isn't a description, again, I won't bid.
3) Don't try to pull wool.
Okay, I'm not the most serious collector, but I do know that Combat isn't ultra rare!

In the last two days alone, I've seen sellers trying to tell me that Ms. Pacman, Empire Strikes Back, Frogger and Combat (yes Combat) are all extremely rare and hard-to-find carts. Funny...in my small collection, I don't have a Ms. Pacman...but I do own 2 ESB, 4 Froggers and 2 Combats. If I see something like that and a if someone is bidding a lot of money, I'll usually e-mail them and tell them that they can get the cart a lot cheaper.
4) Keep the price real
Ok...maybe it's because I'm not a serious collector, but I'm not paying as much for an Atari 2600 game as I would an XBOX, PS2, or PC game. Now if it is one of the extremely rare carts and I wanted it, I'd do it. But I'm not about to give you $5 for pacman or $12 for E.T. My general rule of thumb is no more then $2...again unless it is extremely rare...but since I'm not a serious collector, I've never had to worry about that.
Cap