This looks promising

Like it !
Yes, this is the reason why a lot of people now are joining this project and I hope they already invested good amount so that they will have high chance of huge profit very soon.
What is the minimum amount of investment? I would like to invest in the project, but I worry that my investment will not be enough
Minimum purchase is 50 AST tokens. Get a bonus from 10% to 25% on every token purchase. And at Stage one of All-Stock PreSale, the price is 1ETH = 625AST -> Min = 0.08 ETH. For make sure, you can make investment with at least 0.1 ETH.
As for now, I think it is a good sign to invest in this kind of ICO, Because of the price of crypto coins is in steady phase. And the minimum to invest is not that big also.
Yes, with the value cover of almost major crypto currency now, i think this is the good time for investing for some project look like All-Stock.