:) Hi commic,
You have heard it and seen it posted many many times before no doubt, If it looks to good to be true it generally is.

A good judge of the right pricing for bandwidth whether it is Reseller or shared is:

1gb = 1 - 2 USD

And generally speaking the space to bandwidth ratio should be:

for every 100mb's of space 1gb of bandwidth.

These are the unofficial specifications you should look for in a host you are considering, no doubt others will tell you differently however the fact still remains that for any host to make a decent profit and allow for business improvements etc. they need to charge prices that allow for it or else they simply wont be around in 3 or 4 months.

You will also have some people say that some of the companies you have listed are well known etc., I would do a bit of investigation on each of them to find out why they are well known before considering signing up with any of them as you should do with any prospective provider.

With all that said, if this is a serious business step that you are embarking on then remember that quality will be your main concern not quantity for price. What good is all the bandwidth you can eat if the server is down more than it is up or support is no existent.