Lots of biotech-type things are rapidly getting cheaper. Most notably for this purpose, sequencing and DNA synthesis are both getting cheaper at an exponential rate (to the point that there's a term for it -- the Carlson curve -- similar to Moore's law for computing).
A treatment that costs a few million dollars now will cost a few thousand dollars in a decade or two, assuming all costs scale according to the Carlson curve. In practice, this is probably a bad assumption, if nothing else because a hospital bed alone costs a thousand dollars a night or more, but it does seem likely that mRNA-based treatments will become much cheaper to develop over time to the point where they will be cheap enough to be viable by the time they would actually finish passing through the regulatory hurdles.
Ya, I have heard virologists talking about how many can already do mrna work in their own lab. It's scaling it up that is the expensive part. But I suspect it will just be a matter of new machinery focused on individual production rather than bulk production.
A treatment that costs a few million dollars now will cost a few thousand dollars in a decade or two, assuming all costs scale according to the Carlson curve. In practice, this is probably a bad assumption, if nothing else because a hospital bed alone costs a thousand dollars a night or more, but it does seem likely that mRNA-based treatments will become much cheaper to develop over time to the point where they will be cheap enough to be viable by the time they would actually finish passing through the regulatory hurdles.