Alternatives to cubeamajigs?

Hey all, building my first 4 person mini-cube and was wondering if there are any alternatives, creative solutions, or hacks to use in place of cubeamajigs? Shipping from Hitpointpress is $15, too steep for me, and I would prefer not to support Scamazon. I didn’t want to use ziplock bags as it seems tacky but didn’t have any better ideas. Do I just need to buy once and cry once?