Winning by closing gates

Like any game you can munchkin your way around it or you can take it as it comes.

I'm glad that AH is a co-operative game because in our house we can't play anything due to the competitive nature of the players (ok, me) which does nothing for family harmony.

Yeah, plus the bank run isn't such a great strategy as it wastes a whole lot of time (so I don't see how the term "powergamer" fits in here) which could be used getting clues or closing gates (I suppose that's a non-issue if you gear up from the beginning). While we do on ocasion set out for final battle (rare, depends on ancient one and other starting conditions, investigators, etc.), with the epic battle cards from Kingsport this is a bit of a risky proposition. In non-League play we never play for score anyway, and try to just win by any means - quite often/most of the time this means having to seal 6 gates.

It certainly is kinda suspicious to ditch all your items before retiring or getting a bank loan.
One could rule those out completely by only allowing 1-for-1 item trading (or X-for-X).

I personally find that just a bit too extreme in the other direction, since it
really neutralizes the special abilities of the card-drawers and shoppers with income.

I compromise would be to allow each investigator to 'freely' donate only one item per turn,
in addition for X-for-X trading. The time it would take to completely unload would
make the unsavory tactics infeasible.