An iPhone 4 is a CDMA 3G only smartphone.
Can you please break down the charges on your bill so we can know what you are being charged for? We are just customers here and don't have access to your account or any other besides our own account. Is this your first bill for Verizon Wireless services? A little bit more information is needed to help us help you.
I'm most definitely NOT a VZW employee. If a post answered your question, please mark it as the answer.
As Ann154 has said, the iPhone 4 IS NOT a 4G phone. Additionally, there IS NOT a premium price to pay for 4G over 3G. The price is the same whether you get 3G or 4G, so you are not necessarily paying for 4G, but just paying for network access.
As to your bill being $173 instead of $129, there could be several different reasons.
Is this your first bill? If so, there is normally a partial month(depending on when your billing cycle starts/ends) and then a month in advance charge on your bill. After your first bill, it will only be the month in advance so your subsequent bills will be lower.
Are there data overages on your bill? This could also be the reason your bill is higher. You would need to keep track of your data usage and increase your allowance if you continue to have overages.
Finally, as Ann154 has said, we do not have access to your bill. We are customers, just like you, and would need more information if you would like more help. Read over your detailed bill. All of the charges are explained on your detailed bill.