Suit, Shoes, Shirt, Tie, for MSF program and future interviews?

Wasn't able to secure a summer analyst position but considering an MSF so going to be working a non-fancy job over the summer. Is saving up for a $500 suit supply suit everyone on this forum is talking about worth it or should I get a department store suit like Bar III from Macys? I'm not going to be working a fancy summer job so my budget will be tight.

I think I can afford Indochino or CT shirts. Any other recommendations?

For shoes, I have a unworn Johnston and Murphy black cap-toe which I could possible return to get a different brand of shoe. Should I do this? Is the Allen Edmonds really worth getting? What about Jack Irwin? Any other recommendations

And I don't know tie brands so any recommendations will be helpful