Cat,
I do like your calculations, but I think some more number crunching will yield more clarity. You calculated avg pps for the shops producing all products, but not including the square that the shop takes up. Let's look at household store at RL 8 with level 0 buildings because it is widely seen as the gold standard for making money at that RL. It has 3 products: glass, cutlery, and icebox. You only need to produce one of these items to keep the store happy.
let's say you have 1 stores, lvl 0, sw=150 so you can sell 5 icebox. Requires 1 HI, 1 Steelmill, 1 ore mine.
Income = 109,820, expenses = 46,775, net = 63,045
if you include the shop you get a pps = 15,761
if you make cutlery too, you sell 14, requres 2 HI, 2 steel mills, 2 precious metals (10 spaces total)
income = 261,790, expenses = 116,025, net = 145,765
pps = 14,577
I'll compare that to cafe at RL 0 where you only make icecream and cacao. need 3 FI, 3 cattle ranches (7 spc)
income = 159,750, expenses = 42,865, net = 116,885
pps = 16,697
That is why I like cafe. Now, these numbers only go so far. Nobody keeps their buildings at lvl 0, as soon as you apply ql you can get different results, and cafe doesn't make good score. But, early in the game if you want to make good money, cafe does well.
Best Wishes,
Dave
One-Stroke (slow)
No-Knots (speed)