Question : Problem: Blackberry MDS browser and service plan for Sprint

I have BES 4.1. We have used Blackberry for internet from Sprint. There's Sprint BIS browser. While I was searching in the web, I saw some articles about MDS browser advantage over BIS browser in terms of cost in money.  if I use MDS browser instead of Sprint BIS browser, is it really possible to reduce cost of my current data plan? Currently we pay $39 for unlimited data plan for internet and email(sprint.blackberry.net email. Please don't ask why we use Sprint email instead of our coporate email. Our 3rd party software company insists to use this email.).
In this case, if I switch to MDS browser and remove Sprint BB internet browser, and cancel data plan from Sprint, will MDS browser still work? Or is there any certain data plan I have to switch to if I want to reduce the cost to less than $39? One time, I asked Sprint and they say I still have to have unlimited data plan even though I use MDS browser which makes sense because from my Blackberry to  wireless tower in the city, I still have to use Sprint Wireless network. Does anyone have any idea or experience on switching from BIS browser to MDS browser and noticing cost difference for data plan?

Answer : Problem: Blackberry MDS browser and service plan for Sprint

Pretty much to use the data network on a blackberry you need the blackberry plan. In the case of sprint they have 2 unlimited plans. One that supports Blackberry Enterprise and one that does not. From that price I have a feeling you are already on the one that doesn't. Pretty much you are stuck if you want data.