If it were me, putting a sell order for 750+ and waiting a year or two would be the best option. Other options would include: holding FLDC forever (buying science / supporting research), or sell and learn from the experience.

FoldingCoin is on a half-life distribution, so as the number of folders increase and the coin becomes more scarce, the price should increase, but it's not guaranteed to do that. Holding long-term seems to be a good option, but doing anything is always a gamble.