It sucks financially but this is the opportunity for the wrestlers we support to make their best money of the year. Narrow it down to a few that you really want, support them and pay for a picture or whatever with what you can afford.
Your best bet for free photos is at Axxess, but you'll have to wait in lines and won't get any of the top talent. I wouldn't try to get wrestlers at Wrestlecon outside of the convention setting (like in the hotel or whatever) because that's their time and it would be rude IMO.
The BC Block party has their prices for photos right on the ticket page so it's clear as day. Pay for what you need and don't try to get everyone because it'll cost way too much: https://www.tickettailor.com/events/bcbp/227382
Here's a Clear Fanny Pack if you're planning on wearing zubaz to the event.
Another good choice is the "Clear 12 x 12 x 6 NFL Stadium Tote Bag with Side Pocket". It's $2 cheaper with more room. It's a tote, though, not a backpack.