Pricing for a single SMS is listed on our. For long messages that are split into parts you are charged the cost of a single SMS multiplied by total parts.
Take for example, a message that is 200 chars in length and sent to a destination that costs $0.0075. If the message contains only, it will be split into two parts (153 chars + 47 chars) and you will be charged $0.015 (2 x $0.075) and if the message contains one or more unicode chars, it will be split into 3 parts (67 chars + 67 chars + 66 chars) and you will be charged $0.0225 (3 x $0.075). The message split is only for billing purposes, it will show up as a single concatenated message on most mobile handsets