Honda's are genereally pretty well built and last well – some manufacturers smaller bikes are woeful.
Milage itself isn't crucial, more how the bike has been looked after.
Make sure suspension linkages, swing arm/wheel/steering head bearings have all been greased and replaced where necessary.
As with a pushbike, brakes seize and chains and sprockets wear out if not looked after, even on a 125.
If it's been used through the winter, has it been washed properly afterwards, or are all the alloy fastners corroded and furred up?
TBH, it WILL end up looking scruffy if used all year round.
Varadero's are lovely if you're a big chap, but a bit complicated and expensive if you're not that bothered about image.
If you just want something cheap to get about on, a Honda C90 or Honda CG125 (as per Marges' post) would deffo be the way to go IMO.
Both are ace, in an anti fashion sort of way!