Depends which plan you choose.
All the Beyond Talk plans ($35, $45, and $55 per month) and the $40 per month payLo plans provide unlimited incoming/outgoing domestic(means USA only) messages during your month of service. Messages include Text, IM, Email, and Picture messages.
The $30/month payLo plan provides 1,500 incoming/outgoing domestic(means USA only) messages. Messages include Text, IM, Email, and Picture messages.
Incoming/outgoing domestic(means USA only) Text, IM, Email messages cost 15¢ each with the payLo $20/month plan. Picture messages are 25¢ each on these two plans.
On all payLo and Beyond Talk plans, international Text Messages cost 15¢ to send and receive. International picture messages are not available.
If you are asking about the Assurance Wireless plans, see their website by following the link on this FAQ: http://virginmobileusa.custhelp.com/app/answers/detail/a_id/3340. Then click on the PROGRAM DESCRIPTION tab on their website.