Looks OK to me for the £

are they looking for a mountain bike or a “mountain bike shaped object”

if its the former then tell them it will last a few months, get them hooked, fall appart and be the begining of a long and expensive hobby.

if its the latter for comuting get a secondhand carrera subway, give it a good service, s/h SDG bel air/charge spoon (if its a bloke) and give him the rest as change.

that is a reet bargain