In my experience the hard up privateer runs his (or her) bike for a few years until it's completely obsolete and then sells it for a song, only to see it worth 0000's in years to come.

Or to put it another way, why did I sell my Tz350 for £900,  Tz750 for £1400 and my worst ever mistake a Harris framed TT F1 duke with 4 spare wheels for £3500!!!

Add to that the Jota and Z1a road bikes, countless rd250s and x7s for pennies and an rd400 for £300.

Hindsight is a blessing and a curse...