$270 hour dual for a Duchess??.
$220 hour solo for a Duchess??.
Make the most of it while it lasts!....the first time something goes wrong or needs overhaul, there will be nothing left in the owner's kitty to pay for engine/repairs etc.
With Avgas @ $1.40 and Beechcraft spares paid for @ US$0.75 forex - a Duchess can not be run as part of a (honest) viable business at the above rates.