Of course 500 dollars is a relatively small amount to invest, but if you approach this issue rationally I think it would be nice to invest in Fusion.
Well it is good to stay on the safe side and your choice is not bad but I would have gone for something better and by that I mean the top coins in the market.
$500 is somehow a small amount and does not gives you enough show but the current cost of ETH is also low and I would no doubt invest my money in ETH no mater how low the cost gets. Because one day or the other the market price will return and so ETH will be again the leading coin in the market.