Something's wrong. I have 157 billion AI and for fun I reset and only started the lemonade stand. I bought all the upgrades and got everything else to 400 without starting them. With just 1000 lemonades I was making 20 nonillion a minute. I then started the rest of my stands at 400 and I'm still making 20 nonillion a minute.
My girlfriend loves excel so here is a chart showing the cost to get the next achievement for each item: https://i.imgur.com/W4URvPl.png She also
made one of the cost of each item at each level https://imgur.com/a/GkqYW
 "AdVenture Capitalist"){kind=icon}