For me the tier with holding 12500 tokens is the sweetspot. You get up to 8 WOF spins, get some cashback and you get extra interest on your BTC. I am not sure if going for the top tier premium membership is worth it, but thabks to your investment and topic, we can follow the progress and see how long your ROI is.
Frankly, by my personal experience, it doesn't worth going until the last investment tier, considering how FUN lost value in more than 1 year I'm holding 500,000 FUN on my portfolio. Profit is being made on one side, but I'm constantly losing money on the other side through FUN devaluation... It's like swaping six for half dozen in the end.
Can the scenario change futurely? Of course, the possibility always exist and we may see FUN gaining more traction once again, what would turn this investment highly profitable, however it's just a possibility followed by many risks. So, in my opinion it's still better to stick mainly with BTC investment in crypto market, and when taking part in premium program, I advise doing like you did: 12,500 FUN investment tier.
That is pretty enough to enjoy the best freebitco.in platform has to offer. In January my tokens will be unlocked once again and then I will decide what to do next.
Let us know how you proceed with the tokens you have. It is true, that the value of the tokens has only go downwards and there is no real reason why it suddenly would go up. While I love freebitco.in, I feel like there is not a lot going on with the development of the FUN tokens and I think we all expected more from it.