I am just a hobby pourer, but I don't look for the cheapest stuff, I look for what works.
It's like glue in furniture carpentry. A glue might be more expensive, but you use relatively little in the actual construction, and if a glue joint fails, you've wasted all your labor, and that is the most expensive part of the piece.
The same is true with making baits.
I'd recommend you start with one of the suppliers who sponsor this site, and see if their products work for you.
Then you can find out what successful pourers use, and why, and decide if you want to switch, based on what your needs are.
People who make and sell baits can't afford product failures, so they use stuff that works for them every time.