Hey damiano... The shares are each 4% of the miner (1/25, ~4Gh/s) no matter how many I keep.  All 25 belong to me as of right now because the miner is paid and my address is on the order.  But if you want to own a piece, just make me a reasonable offer 

My ideal outcome would be to keep 5 and sell 20 for around 80-100 USD (1.0-1.5 BTC) each.  BTC bids I will have to accept depending on the USD exchange rate since I paid for the miner in USD.  But I might not get interest for 20, I might only get bids for 10.  Or if the bidding goes way up for all 25 shares (wishful thinking maybe  ) I will sell all 25 and use the proceeds to upgrade the miner.