I'm not sure cost is the issue. In fact cheaper actually AGGRAVATES the underlying problem. The issue with Alchemy is that if it produces results on par with or better than standard powers, then it undermines the power system (why not just acquire superior alchemical means to do things). Even if its JUST on par it totally trashes the resource management system of 4e (unless its entirely restricted to at-will power level, and even then it produces some unwanted effects). Making the stuff cheap or free just exacerbates this issue. In fact making Alchemy significantly expensive but also substantially effective might be a BETTER solution, however it would require effectively writing a whole new subsystem. Kinda OT of this thread, though its an interesting topic to pursue.
The problem with cost is very straightforward:
Alchemy Savant gets +Int to hit with an alchemy attack on an AP(aka standard action)
Alchemy Savant gets an encounter power that lets them use an attack as a minor action
Alchemy Theme gives 1 free alchemy item per encounter.
i.e. an Alchemy Savant probably ought to be using 5 alchemy items every 3 encounters or so. It only gets 3 free items, though...
And in the context that alchemy items are basically weak at-wills once you hit Paragon? Um...
That's why the Wand Golf Bag+Arcane Familiar works out really well for an Artificer. The Artificer has his regular powers and then he has a variety of encounter/daily options from his alchemy that mimic Wizard powers. As an example, you could pick up the following items:
+1 Master's Wand of Magic Missile(3rd level item) - Magic Missile 1/encounter that includes a push 1.
+1 Master's Wand of Thunderwave(3rd level item) - Thunderwave as close burst 1/encounter
+1 Wand of 1st level Encounter Power
+2 Wand of Icy Rays(8th level item) - freeze ray
+2 Wand of Precise Color Spray(10th level Item) - adds +1 to hit with Color Spray, critical hit with 1st roll of Color Spray - radiant flamethrower
+4 Wand of Dark Gathering(18th) - tear gas grenade
+4 Wand of Prismatic Burst(18th) - upgraded flash grenade
+5 Wand of Mass Charm(23rd) - confusion gas?
(throw in a wand of utility or 2...)
If you upgrade the items when you're about 8 levels higher than the item, your to-hit with them, assuming a starting Int of 20 won't be that bad. They have an interesting effect in combat and make for a very wide variety of options. I typically consider them a 'I'm a 1st/2nd edition Wizard with spell slots' way of going about things, but easy to refluff into alchemist.