If I calculate total cost of bike, plus bling, plus service and fuel, plus, plus, plus, my total comes to R9.77 per km - slowly dropping as the km's climb.

If I only take fuel, service, tyres, insurance etc. it comes to R0.74 per km - slowly climbing as the price of fuel, service, tyres go up.

However, if I sell the bike sometime in the furture I will subtract that amount from my total cost and only then will I see what the bike cost me over the whole period. I keep record of every cent I spend on the bike and created a spreadsheet where everything is recorded. From there it is easy to manipulate the information for every possible scenario.