Check locally for crickets. They're supposed to live like 1-2 months so you'll have to buy them usually every 4-6 weeks and online has always been more than what I could find locally. My local store is charging me like 16 bucks for 1,000 crickets where online it seems like they cost 20+. If you can't find them local then I'd plan on breeding, but I haven't done that at all or looked too much into it. You'd need food, water crystals (or something to give them water, can't use a bowl), a few containers for different stages, a few containers with some type of substrate for eggs, and then an incubator seems pretty important. Incubator wise you can use really simple set ups, you can hatch out cricket eggs in the 70's, but they take longer to hatch than if you incubated at 90 degrees. So setting up a cooler with an heat source and a dimmer switch can do really well (if I breed them I'll probably leave them in the garage or in a box outside since it's like 90 degrees for 9 months out of the year).

They're supposed to be super easy to breed though because they grow fast and breed crazy well. A dollar's worth of crickets can get your breeding program started and you could hatch 1,000 crickets every week in like a month. And once you have them started you shouldn't have any issues maintaining the production. You could wipe out all of your bugs and spend minimal money to get back to where you were.