General trend for new heads is like 130-150 but if all of them agreed on one high price it could be anything
Players are selling unplaced pumpkin heads for around 200 diamonds right now. Keeping mine till prices rise. (Placed heads arn't as wanted as unplaced.. and yours costs a little over 100 dias, like 40-50 diamonds.)
Usually, when a new head comes out, it goes for around 150-250 diamonds. As the time goes on, it increases in value.
I bought a 2K15 Pumpkin Head unplaced for a beacon (About 90-100 dia) Plus 14 dia. I think the price does very, and depends on who it is from. Some sold it cheap cause they got a lot, some more cause they only got one. I'd say that unplaced is going to be around the 100-130 dia, depending on how it stabilizes. You have a placed one, so I would say the value will be only about 40-50 dia :T Some won't even buy it because they want unplaced. Most heads like this as time goes on will become more of value as people loose theirs, only a few have them, or they just don't sell as much. My Bunny Head unplaced for example was for around 230 dia, but now most skygods and donors are saying around 400+ because of lack of selling, and lack of unplaced heads.