I recently made a complete upgrade package with all improvements (kernel and kexts built specific for the system) and custom DSDT mods (added the custom Apple devices MCEH, PNLF and SMS0, HDEF fixes, and power button fixed) + EFI strings (enabling audio, video and ethernet fixes...) for someone...
As a thank you he just deposited 100$ on my Paypal account...
I tend to say to this person: a really big thank you for that...