Current Events > attn: photography nerds, need help

(+) Yeah! (+)

I was advised that I should try to squeeze as much life out as possible on my barely used canon t3i. I bought a 50mm prime lens a few months ago used for pretty cheap $100. I started going to more museums and conventions, and with the 50mm, I have to stand pretty far away to get a more wider shot. I know this isn't going to be possible in crowded area. I am looking for a good wide angle lens that I can purchase used at a low price since I am just starting out as a novice photographer side hobby. I am not saying I am not happy with it, but I think 50mm is too zoomed in for my use case at this time.

I looked into this one. Does anyone have any other recommendations that is around the same price?
https://www.bhphotovideo.com/c/product/802697265-USE/canon_9522b002_ef_s_24mm_f_2_8_stm.html

Or, should I just dump the canon t3i altogether and invest in a used sony a7III (my budget is about $2,000 for body + lens)? The sony side does not have cheap lens like canon does.