A Big Difference between the prices of USB Modems of Telenor, Zong and Ufone

First of all Telenor offered the USB Modem with the price of Rs.11,999. I think, It got a great success through out the Pakistan becuse it was a new thing to the IT industry. Then, ZoNG Launched USB Modem after that and its retail price was 10,999. It was cheaper than the last one and great thing is that you can use unlimited GPRS or Internet paying only Rs.400/per month where the usage policy of firstly discussed was per MB. And soon after that Ufone offered USB Modem with the free use of First 6 months and its Retail Price is 6,999. And its usage charges are per MB. It also offers upto 2GB usage of data upload or download for Rs.500/+tax. But Zong offers unlimited usage for Rs.400+tax. Now the question is that What is the best Modem, I think it depends upon the needs of customer. And what do you think?