There is the same model rig in Europe for sale listed at $2 million, of course no way to compare condition to the AMEP rig which had little usage in Mexico assuming that's it's total history. If Bitters got a "deal", it may have been for $1 million or just under or over. From the work being done on engines, etc., I would guess it was used for much more than a few water wells.
Cash is King until further notice!!!
My comments on companies are usually my opinion of long term success (years). The PPS may go up or down greatly in the meantime depending on the number of greedy suckers with money.