Industrial control components, from what I can tell, are a way to slap together something that works really reliably, at rather high cost, but with lower develo

Industrial control components, from what I can tell, are a way to slap together something that works really reliably, at rather high cost, but with lower development time and engineering costs. So if it costs you $5-10k to build a washing machine with such components, that's not really a bad deal, because how much does it cost to engineer a modern washing machine? A lot more than that. For these street toilets, the question is: how many toilets are there? If it isn't a large enough amount, the engineering cost to develop something with a lower per-unit cost won't be worth it.