There are three components necessary for functional geopolymers. Actually there are five, but in practice there are three elements which supply the five necessary components. The five are alkali, soluble silica, soluble alumina, water and fine particles (usually silicates and aluminates) that are not soluble, or at least not dissolved.
The three ingredients are an alkali solution, a soluble aluminosilicate and a mineral filler.
Some of these I have found in large quantities very cheaply (Hydroxide). Others, I have not found a reasonable source for at all (fly ash). If you know of good sources of any of these, let me know. Perhaps I will be able to obtain them, and compare the results with what I already use.