At my shop we use a few inks... rutland, tri-ink, and wilfex. I like rutland the best. It's all up to personal preference. I am not sure which one is cheaper though. I would call a supplier (we go through Martin Screen Print supply), make an account, and then ask for some samples. They are usually free and that will give you a chance to try a variety out before you buy them. I hope this helps.
