I think on really large heating loads, over 200k btus, plate hx might make economic sense, but from a strictly cost perspective, I think CSST coils are a fair bit less expensive for loads under 150k.
Maybe I am biased, but coils eliminate some pumps and hardware, which are not necessarily a cheap date.
Having said this, we just had to raise prices on our products. Steel and everything else just continues to creep up in cost. We absorbed as much as we could before doing so.
Pricing pumps scares the hell out of me.
Last winter I changed over my system to 12VDC Gorman Rupp circulators to see how things worked (it is what I do!). They are quiet and have about the same performance as 007s. I started with some Chinese pumps with similar specs. They worked but were too noisy for me. Not crazy loud, but audible. We have been using different Chinese pumps with solar heating systems, operating off PVs. Some were great, some were awful, failing prematurely.
The Gorman pumps have been great. No issues even if i did something stupid like forgetting to open a valve and having the pump dead head against it for a couple days.
If we put the house up for sale, I am going to have some explaining to do...