I believe there's a formula for this, something to do with age and mileage? 

for newish nice small bike:

80% of original price minus 1baht per kilometre

13 hours ago, papa al said:

for newish nice small bike:

80% of original price minus 1baht per kilometre

Find a Honda  click with 40,000km on it and u will get it for free then 

1 hour ago, speedtripler said:

Find a Honda  click with 40,000km on it and u will get it for free then 

40,000km is not newish.

But yes,

best give it to her family 

FREE.

To buy or sell? Where is also important. If in BKK you can go to auction and get a good 1 year-old one for about 20,000.

7 hours ago, VocalNeal said:

To buy or sell? Where is also important. If in BKK you can go to auction and get a good 1 year-old one for about 20,000.

Where in bkk is the auction? 

Contact Bangkok Scooter Rental. Phone after 10 am talk to the farang (Mark?)

For a fee I believe about 1500 baht, you go with them to the auction and they show you the ropes and guide you through the process of paying and transfer. 

The weekly auction is for bikes up to 150cc most are repossessions. For larger than 150 the auction is once a month. Something like that....

You will need to take cash and be prepared to ride your purchase home.