What is a good alternative to lattice?

There isn't a lot that would be cheaper. The only thing I can think of is maybe bamboo blinds, but they won't look any better and they won't last more than a season or two before they look like crap or fall apart. Coroplast would be a bit cheaper but will sure look like it. Wire mesh fence with vines growing on it, maybe, but then that might be only seasonal depending on your climate and will take some care or maintenance.