Looking for a NP-85 battery?
At this point they are next to impossible to actually find. Yea, they'll tell you they got it but when you get the shipment it's something less than what you ordered.
What's the difference" The 2000mAh represents the maximum service life per battery charge. At this point in time the 2000mAh battery is the max you can reasonably expect to get. 1900 is less of a performer than 2000 and 1750 is less than 1900 and so on.
Most tech savy have figured this out and won't settle for anything less, the retailers, those that actually had the item on the shelf, have run out of the actual item and many of those that definitely know better are even pushing past the legal definition of "false advertising" to get "SOMETHING" out the door. I expect that they're hoping that you either won't notice or won't actually sue, this btw, is a FEDERAL offense that you could actually do time AND a fine for. One or two of you will probably not be able to afford a FEDERAL suit but five or more will find it in range of your pocket.
It will probably be several weeks or a month or so before any 2000mAh battery is actually on the shelf and when it does it's a bet that the $4 -5 price tag per will be relaced by something near twice that. If the asking price is above $12 per, keep your money in your pocket, at least in your bank account, or in your old sock, whichever applies. (The $12 is a bit overboard but allowable if you're really that desperate.)