Is there any real differences between cooling fans??

[ThePrIsMcAURA]

Just wanted to know this, I know barely nothing about cases and cooling.
I have a mid tower case with an extra spot for a fan. I live in a pretty hot area in summer where we get to 45 C. I want to get the extra fan just in case.
I was told that some fans are better than others because they last longer. Is this true??
I went around to a few computer stores and they all said they were the same but they didn't sell any fans separately. They tried to get me to buy a brand new case.
If there is a big difference could somebody tell me why and please suggest which would be best to get.
Thanks in advance

 

[resinboy]

Fans come with either a sleeve bearing( bushing) or a ball bearing. Ball bearings last longer. They also come in a higher rpm( moves more air for the money, but louder) or a low rpm .
I buy my fans from http://www.2cooltek.com. Great service.
Bear in mind that it is just as important to get the hot air out, as well as the cool air in. If you have room in the upper rear of the case, stick a couple of exhaust fans there as well.

 

[ThePrIsMcAURA]

Thanks for the reply.
Much appreciated.

 

[Ulysses]

Bigger is better.