But then again, you often just upgrade these items, going from say boots of speed to power threads, making slots a lot less limiting. In my experience, slots matter only in middle game, in early you're too poor to buy 6 items, in late you upgrade only anyway.

Although got hit by irritating limit in Secret Shop once and had to return to base to drop one item to stash to actually get what I bought, but I don't remember what combination caused that >_<