From what I read on the Majesty forum, adjusting the valves is akin to rebuilding the engine on some bikes. It seems that many just ignore the valve adjustment, and ride it for as long as it runs, or sell it before it quits running. Valves seem to be the biggest issue on maxi scooters, I don't know why they didn't design them so they are easier to get to, or use hydraulic valves. I chose the Zuma 125 over the PCX150 solely based on how hard it was to do the valves. Zuma, 15 minutes. PCX, 3 hours.
I won't spend more on a bike than I think it's worth, but if it's a good deal, I don't seem to have a problem buying bikes I don't need.
2002 Vulcan 750, 2013 Royal Enfield B5
2001 XT225, 2009 Genuine Stella
1980 Puch moped