maximum frt size in the wild is 22" 50 lbs, i have seen people keep them with lots of different fish but no other turtles unless you have alot (600-700 gallons per turtle or more) of space and alot of hiding places they are especially mean towards thier own kind breeders usually dont keep a breeding pair together full time males have been known to kill females
and average price is usually$400-$500, why wouldnt you buy one know before they are completely illegal which they probally will be in the US eventually unless you already own legal ones then they cant take them away
FRTS are the only true aquatic freshwater turtles they do not need basking spots but do need a sand "beach" for laying eggs if they were to breed