For years my go-to resource for all things climbing has been Atomik. Atomik has won awards for their service and does great business. However, I am judicious when on how I spend my dollars. So, sometimes I look around for other kinds of deals.
I find bolts cheaper here: https://www.fastenersolutions.com/11205-p-102.html 5/16-18 X 1-1/4 Alloy Socket Head Cap Screw
From time to time I seem to get a hankering to build a climbing gym. I built one for my little girl and one for her cuisines.
Here are some links for the supplies I find necessary.
But I think that fastenal might have bolts cheaper
I also have gotten t-nuts cheaper elsewhere, but I can't remember where.