hey guys i live in new york.i just bought a new bb bold 9700 on ebay. it says its brand new, unopened box and is unlocked. im thinking of putting in a t-mobile prepaid sim card, will i still get all services from blackberry such as the pin and blackberry messenger??

Not without a blackberry data plan.

the t-mobile prepaid has unlimited talk,text and data for $50 per month. will that be sufficient ?

Nope. BlackBerrys are a different kind of animal. On pre-paid with TMO you'll get phone and sms only. TMO doesn't offer pre-paid BlackBerry so you'll have to go on contract if you want email, bbm, etc.

The carrier's mobile data service will not work for BBM and other BlackBerry data services. You need the BLACKBERRY data. See blackberryfaq.com.

Typically the blackberry data plan is in place of and not in addition to a carrier data plan. Ask, but I doubt you can buy the blackberry data plan on prepaid.

And unless it is a T-Mobile branded 9700, you will only get 2G (EDGE) speeds after you add the BlackBerry Data Plan.

i wanted to buy a bb off ebay, thanks guys i'll just wait until november and get the data plan

Make sure that you read this first: Buying a BlackBerry off eBay - BlackBerryFAQ