The traditional
view is that this is a very small amount and, therefore,
Socrates is being ironic here. In effect, purchasing
wisdom for this amount is a real steal (sort of like getting a brand new
Corvette for the price of a used Chevy sedan). More recently, some scholars
have suggested that this was not a small amount for that period of time.
By this account it is a sizable sum which would, nonetheless, be worth paying
if Sophists really could dispense wisdom.