Do you have the standard kit lens that comes with a T3 ? The 17-55mm zoom? If you do you already have a WA lens. Anything down to 15mm is considered WA.
So if you want an UWA (ultra wide angle) the best choice is the EF-S 10-18mm f/4.5-5.6 IS STM Lens. It is under $300 bucks.
EB
EOS 1D, EOS 1D MK IIn, EOS 1D MK III, EOS 1Ds MK III, EOS 1D MK IV and EOS 1DX and many lenses.
