Depends who your service provider is. Since you're using the T616, I'd guess you're stuck with AT&T, and they rape you for all you're worth -- mMode's base charges are pretty high, and on top of that you pay for downloads as well -- ask them for details. muwap allows for free (and fairly good) previews and "pre-listens", so you should be able to download only what you want on your phone.
T-Mobile currently offers free
WAP access to their pre-paid (EasySpeak) and post-paid customers. This *may* change at some time in the future, but it is still free as of today.
Happy Fourth!