The main reason I was considering a full-automatic tempering machine was to have a dosing pump. I then found Hilliard makes one that which costs significantly less, though still around USD$5,000.
Researching various pumps it seems that peristaltic pumps could be a very affordable way to hack it together. There are even a few people 3D printing pump heads through which you could put a food-grade hose.
Are there other cheap options I should be considering? Has anyone gone the DIY route and have advice to share?