Looking on the net I see...EN-EL9 batteries for my camera. I see them as high as 58.00 and as low as 9.95. Is there a difference other than price?

Generally the only difference is the name on the battery. Nikon doesn't own a battery manufacturing plant, they just slap their name on it. Just make sure the mAh is the same or higher. Otherwise, go with the savings.

Thank you!

I bought additional non-Nikon brand batteries for my D60. They worked, but they're dead after only a couple of years while my Nikon brand batteries continue to work just fine.

I've had the opposite luck with 3rd party GoPro, Cannon, and Nikon batteries. But I buy either RAVPower or Smatree replacement batteries.

To extend battery life, fully charge and discharge the battery for the first three to four cycles, then don't let them get below 25% before recharging. Don't overcharge them or leave them in the charger for any length of time and when storing them, store at 40 - 50% charge. About the worst thing for a li-ion battery is to subject them to heat when fully charged.