Although the Jobo Expert drums are wonderful to use, many people use the BTZS tube system and swear by it. It is definitely a (much) cheaper alternative, and you could build your own.
I was always wondering on how to bundle 5-10 of those tubes together in a similar fashion as the Expert drums. The thin walls of the Expert drums have a benefit for temperature uniformity, but for (near) room-temperature processing that may not be an issue.
Honestly, I still can't get past the irony how a plastic drum like the 3010 sells north of $400.