You really don't want to be that cheap with more complex rinds. They take some careful parameters to be consistent and tasty. I would focus on the rind management.. creating the right conditions, controlling the temp/humidity parameters, etc. Yes, you can extend the life of b linens and propagate your own, but unless you already have some experience and equipment (eg, you already harvest your own yeast for homebrew). I would never add a complex rind to milk. You're just asking for trouble with that approach. Homebrew morge (and old-young smearing), fine, do what you want, but even that has its limits because high surface aW and food safety goes to hell because of listeria.
If you want to really extend the life, you can focus on two aspects: 1) increase CFU count in the wash 2) use basic morge propagation
for 1, what you do is use a spray bottle and aerosolize the spray. For 2, you can use a tiny little bit and scale up the morge. eg, make a pint to start with a tiny pinch, then check pH, add a bit of food if need be, and then scale to a half gallon. You can quickly propagate and have enough, similar to doing a primer approach with DVI mothers. Or just spend the money and focus on quality