Anyone know of any good bolt on top tube bags for a gravel bike that aren't over $50?

i just got a strap on one from rockbros for $10 and used a soldering iron to make two holes for the screws to through.

That's my backup plan if I can't find one ready to go.

I like my Mag-Tank from Revelate Designs. Easy access magnetic flap and a velcro strap around the steerer for added support. Thin enough that my knees don't hit it and not too tall.

https://www.revelatedesigns.com/index.cfm/store.catalog/cockpit/MagTankBoltOn