I have tried several diffent ways to optimize my gluing station and save money while doing so.
I invariably always forget to wash out the glue up brushes and they wind up drying and are hard as a rock. Instant garbage and I have to go get another brush. I tried keeping them in plastic bags with water or a coffee can with water, but I invariably forget to place them in the container or I knock them over and spill water all over my work area.
If you go to the paint department at your local hardware store, about the only thing you will find is a five pack of brushes selling for around $5.00
This can get expensive over the coarse of a large project or two.
I have looked for a cheaper glue up brush and several years ago I ran across a very cost effective solution. I found acid brushes in the plumbing department. They are usually used for flux and other plumbing greases applied to pipe joints. They sell for $1.40 a five pack. All the ones I have seen have an aluminum handle and are about 4 or 5 inches in length. They work great and if you accidently forget to wash one out, you are not out as much money.
Hope this helps.