Wa Alaikum Salam.
Then avoid buying used bike, unless / until you have someone expert with you who can judge the complete condition of bike.
It may also be sincerely avoided. To me, it seems like a Gimmick. Do not fall prey to it.
To me, brand new Honda 125 seems a better option (however uncomfy, old engine tech. etc. it is; it is still reliable than these Chinese bikes, with difficult / no availability of parts, bad resale, etc.)