or get stuck and not be able to sell it back for 1 sat .
+1
It is obviously the risk of buying cheap coins, cheap coins with 1 satoshi price are likely just garbage coins with so low trading volume and only has huge number of sell order with no buy orders at an exchange. It is not possible for this type of coins to get better price but it will not be in a day.
If he want to do it then he should not do it with a lot of money and he should take a look deeper about the coins itself. Means he should not buy all those 1 satoshi coins.