T-Mobile USA's pre-interest page for the Sensation 4G went live yesterday, and now the carrier has confirmed pricing for the HSPA+ smartphone both on and off-contract. As usual for a high-end Android smartphone, the Sensation 4G will be $199.99 with a new, two-year agreement (with mandatory voice and data) after a $50 mail-in rebate. If you'd rather not be tied down to that agreement - and who can blame you - then T-Mobile USA will also offer the Sensation 4G contract-free for $549.99 plus tax. That then allows you to take your pick from the carrier's various plans, use an existing SIM, or go prepaid if you'd prefer. The T-Mobile Sensation 4G is set to land in Target stores from June 12, with wider availability in the carrier's own stores by June 15. Check out our full review over at SlashGear for all the details.