Having corresponded with Dave Slagle, I don't know how he would feel about my posting prices for his SUTs. Each would be designed for the two cartridges (Allnic PC1 Supreme and Benz LP-S) I use in my system, because they have very output. Suffice it to say he has been very responsive and helpful via email. I will add that your observation that "they're probably not cheap" is likely to be accurate --wallet dependent, of course.
Thank you very much to everyone for their suggestions. Decision is still pending, as it's a big one for me. I generally aim to make a single purchase and make it as good as I can with the goal of not often having to repeat. You know how goals can be, though...