Instead of Agave, which can spike insulin, it IS sugar ... try Stevia, a natural plant sugar substitute. I grew stevia last year, harvested it, dried and turned to a lovely, extremely sweet powder for my ice tea etc. But it is cheaper to buy NOW Stevia Glycerite (liquid, easier to dispense than the powdered version).
Regarding chia seeds ... The cheapest I've found online right now (I've purchased it in bulk from 2 other sites but prices are going UP) .. is chosen-foods.com, but in bulk. I use it daily in my protein shake, in food, on salad etc. I go thru lots of it, was buying 12lbs at a time but the cheapest per lb I've found is now 25lbs bulk. I store it in the fridge but it doesn't need special storage.
Flax seeds are also great (but chia are better) ... MUCH cheaper under $1lb. Do not buy flax meal, make your own. Flax seed do not have to be specially stored to keep their nutritional value but once it is ground into meal it is only good for 1 week unless frozen or refrigerated ... you never know how long it has been on a store shelf.