THe CFIDS Association Research Initiative. The reason I'm not saying WPI is that I think there's enough outside research going on with XMRV to get it figured out. The outside research community will figure out what proportion of CFS patients have XMRV, and if they find that a substantial proportion of them do, XMRV will be drenched in funding. Essentially WPI came up with such a exciting discovery that the rest of the research field will more than help carry the ball. If XMRV works out its future funding is set!
The rest of the research field is not. XMRV won't be found in everyone and it's still one piece, even if a major piece, of the puzzle. There are many really intriguing topics that are dying for funding. The CFIDS Association Research Network/BioBank/Data Storage program has the potential to increase our knowledge of CFS rapidly. This is where I think you'll get the best bang for your buck long-term.
It depends on how much money! I've often daydreamed of winning a major lottery jackpot and then what I would do with all that money.
One of the big things on my daydream list is setting up housing for those of us who are homeless because of this illness as myself and my partner are.
Also, help for those of us who are barely eking out life at times because we are not fortunate enough to have family we can turn to for help, or what family we have is unable/unwilling to provide enough help. Really, at least here in the U.S there are not programs set up to deal with anything like this. I could really use someone to help grocery shop or projects that need doing which require physical work beyond me (like often laundry as we have no access to washer/dryer due to our MCS). But anyone who can help wants money (understandably so) or the program funding does not cover people with illness such as ours.
I remember how frustrating it was 8 years ago just before I became homeless. Had lost everything due to my MCS and asked the Red Cross for help. They said they couldn't possibly help because though I had nothing but the clothing I was wearing, I had not had a fire. At that time I also had a friend who had just lost half their stuff to a house fire and the Red Cross gave them vouchers for clothing, furniture, food, temporary shelter and then a huge check to help with moving in costs on a new place.
This has stayed with me as a good illustration as to how few services are willing to help with these less accepted illnesses and has certainly helped to keep my partner and I homeless these last 8 years by greatly making it much harder to dig ourselves out of this hole.
A small amount of money - certainly research is a top priority.