Yeah， thanks for your good advice and i would say almost all “ist” hacks are reserved or liquid prices by the registry，and the *St*regI'm going to go out on a limb and say 500-700, but from a domainer standpoint the value is less because of the slightly higher (that average) renewal fee while you wait for the right buyer.
It is a smallish market for the name but you have a 1-word hack that accurately represents the entire topic of naturism. Almost all naturist and naturism names have sold around $100-200, but there were 1 or 2 in the $2000+ range. Yours is perhaps slightly better than average, plus as time goes on names get bought up and prices often go up, so it remains to be seen what future naturism names will go for.
Some .st hacks have for decent prices in the past, with names like egoi.st ($1250) and bla.st ($4100) going for high prices. A possible reason for so few .st hack sales on record is that there are only so many realistic "ist" domains out there and all the good ones have been taken.