There is a very simple solution to the low-level item problem:
They are too expensive. As we can't change that, simply make all summoning spells 2 times as expensive.
As long as you get one or more summons for the gemcost of the lowliest items, no-one will ever make those as the summons give much more "bang for the buck".
PS: I like dropping some Stinger and Black Tower Shield on indie commanders. Not really cost effective, but fun
