I am not sure how RadioOpt Traffic Monitor is totaling your data usage on BlackBerrys due to API changes RIM made ages ago but it may be worth a shot. A friend of mine has been trying to make it by on AT&T’s 200MB BlackBerry data plan and told me he has been using RadioOpt Traffic Monitor. The app does seem to be working for him though it does have some questionable items in its user license but still I thought it would be worth mentioning.
RadioOpt Traffic Monitor is free and ad free in App World. Let us know what you think if you give it a spin!