I wouldn't be surprised if the FUN price in BTC equivalent dropped to 1 sat or even lower soon. And I wonder how freebitcoin will display the price in the buy/sell section in that case. If the situation with the spread will not change, then in this case, you could buy a FUN token for 1 sat, but selling it would only give you 0 sat, ~
I believe it won't be like that. There is an easy solution of this. They will allow the users to buy 1 FUN tokens for 1 satoshi. And users will be able to sell at least 2 FUN tokens for 1 satoshi, 3 FUN tokens for 2 satoshi, etc. The system won't allow the users to buy and sell 1 FUN tokens if it's price goes below to 1 satoshi. Users have to buy/sell more than 1 FUN tokens to adjust the price in satoshi. Adding one more decimal point for the BTC could be an alternative solution, but it won't be perfect there.