Electric Ride On Cars

I want to buy one for my son for Christmas. However, I looked on Amazon and there are so different. Some are cheap, like $ 40 whereas others are $ 500. I can not understand what makes one different from another. What do you recommend? And where are good places to buy them? Thank you very much!

http://www.toysrus.com/product/index.jsp ...

We got it a year ago for our older and you are about to buy one for younger. I see that I was not very good reviews but honestly we love. He is a decent price and they have a shot with him!
We do not have to worry about them falling because the seat sits, you walk while driving through the neighborhood and I never battery issues, and it was pretty easy for them to learn quickly.

We have a fire truck from Toys R Us, it was $ 300, but its really awesome.It water spray, a hatchet, a speaker and is very big ..
I like the more expensive b / c they have lots of fun things with them, but cheaper to do the same thing.
We have one that was $ 20 at a garage sale that we take camping and fun
I see them at Walmart too