Boof, here's my Al Green Accountancy Skills;
My favorite board, my 9'6 Pintail from Bob... only about $1200 or $1250 including freight. Brand new. On sale. Seems that people were scared of the lovely pin tail... but in truth I'm lucky to have the point breaks to bring it some justice... Sorry I digress!

$1250 Pintail - surfed probably 50+ times already. Say 80 hours of surfing. Condition is 99/100. This board could last me 300 surfs, or 500 hours....
That's $25 per surf so far. Might end up at $3-$5 per surf session... $20 would cover fuel, wetsuits, wax, and a banana...

The KTM - probably 6 rides per year, at roughly $750 to $1250/year = probably $200 per session.
I know other guys who do more riding, but they would spend $6,000 over 3 years, with 40 session... still $150 per session.