The simplest ones are way more efficient than the quality ones, which are also more efficient than the iridium ones. Why would I "upgrade"? I can see maybe upgrading to quality just for the quality of life of dealing with straight lines as a player (but still suboptimal efficiency wise), but iridium certainly not. Don't get it.

Going by item values:

Simple = copper (60) iron (120) = 180g, 4 tiles = 45g/tile

Quality = quartz (50) iron (120) gold (250) = 420g, 8 tiles = 52.5g/tile

Iridium = iridium (1000) gold (250) battery (400) = 1650g, 24 tiles = 68.75g/tile

Plus of course the higher tier ingredients are in reality more valuable even still than that because they are much more access-limited than copper and iron and such. Let alone the higher tier sprinklers not even being available in recipe until later.

The farm is absolutely massive in size, and if you don't have to water, you don't have to visit most crops, so they can be pretty far out there just fine. Space really isn't an issue.