Is Canon USM worth paying twice the price? I have a Canon T1i Camera.?

It depends. Do you want your lens to be wider or not. If you want it wider get the 55-250. Also if you plan to upgrade to a full frame sensor I would gut the 70-300. I would say save your money and buy the EF 70-200mm f/2.8L IS USM or not as good the EF 70-200mm f/4L USM.