Depends on server economy.I bought it once for 50 silver, but i beive the enchanter got a skill add out of it so the enchanter may have cut me a deal, but since then I have seen it sold for 75 silver as a standard.
I sold one for 1g 20s because the guy came to me. He just said WTB Minor Beastslaying and so I popped in and said "I'm your man". Didn't have mats so I checked AH prices and bought mats, then transferred price to him. I pocketed about 6 lesser magic essences too after my 40s pure profit. Good times...