Now that there has been official confirmation that T-Mobile will be offering the Z10 starting March 26, it looks like the German website is the first to offer the device for sale. You can purchase it for 529.95 Euro ($688) off contract, and as little as 149.99 Euro with one of their top tier two year contracts.
Have yet to see the T-Mobile USA site offer the device for sale, but we know it will be coming soon enough. You can order the Z10 on AT&T now, and starting the 28th from Verizon. Find out where else the Z10 will be sold in the USA here.