Before our trip to Thailand in October 2008 I bought a second battery for my D70s as I did not want to take a charger with me. We stayed about 15 days, so two batteries should have been enough. I read a lot of articles and forum threads to find out if it is worth to buy a original Nikon battery of if a third party product would do it’s job. Finally I decided to buy a Hähnel battery: A third party product but not a no-name product.
It didn’t work. I charged it once and the battery gave up after the first shutter release. Great.
So I decided to search an official Nikon store in Bangkok to buy an original Nikon battery. We went to the MBK Center and I bought one. The price for the original battery was the same as here in Europe.
It was an EN-EL3e so I hoped I could use it for my new D90, too. But after one or two times of recharging this battery gave up, too. I contacted the Nikon support and mailed them a photo of this battery and they told me that this was a fake Nikon battery.
The conclusion for me: Yes, it is worth to buy an original battery (although third party batteries might work as there are a lot of people using them) and, if you are to buy an original, have a look at the bottom and be sure that there is a serial number. Especially in Thailand! There is a Nikon site with photos of fake batteries.
It depends on lots of things. I bought a 3rd party battery, the exact model as yours to use with my D90. It is still working just fine; the crucial test was a time-lapse video during a -20 deg C cold winter night. It gave up after about two hours of shooting, a result that I was satisfied of.