HOw do we get past the hump (if that is the right term) where there might be a catch 22 of without a promise those good mightn't be able to turn on plans to use such funding and build the structure needed, but as soon as it sounds like a metaphorical tap is being switched on somewhere I assume you get the usual stampede of a certain type chasing it with their hands out and making claims of entitlement.
The thing I would see is researchers feel entitled that the government would fund their research (they obviously think it is important). The government should have some notion of strategy - what are the major research problems going forward, do we have sufficient skills/resources in these future areas of importance and if not how is that changed. An organization like the MRC has been set up as a club which funds existing research groups assuming other existing research groups think that what they are doing is ok (or marking with mutual benefit)
We have a situation where post viral illness is affecting large amounts of people (count how you want) both in the UK and across the world. Within the UK there is an economic cost (care, healthcare, opportunity cost in loss of labour). For the UK as a country we miss out on the possibility of UK industry taking advantage of research etc. We also are more aware of pandemics and the need to plan.
So I would argue investing in ME and other post viral disease is necessary. And I would say doing so in an organized way to maximize resource reuse and skills development helps reduce cost. I'm not worried about the BPS lobby I don't think they are taken seriously by decision makers now -- there work has been shown to be poor quality. We also hopefully have signposting of areas from Decode.