Leave normal sprinklers recipe Quality recipe would be Sprinkler + Gold Bar + Refined Quartz Iridium would be Quality Sprinkler + Iridium
Plus battery And there's a mod that already does exactly this https://www.nexusmods.com/stardewvalley/mods/2983
Using your old sprinkler as a material sounds more useful, so I like of this idea, I never bother with regular sprinklers because they don't pay well for their cost. Also, iridium sprinkler should cost at least 20k on Krobus to be on par with other endgame upgrades.
i would say i more less agree, the first sprinkles you basicly jump over anyway, going for quality one right of the bat there was also the idea where you could change how sprinklers behave, that would be nice too like this on e https://www.nexusmods.com/stardewvalley/mods/833
