$10 ?
I know that I push for quality optics, which generally are relatively expensive. Granted, there is a point of diminishing returns - a $1,500 zeiss is not 3 times better than a $500 Elite 4200 or Nikon Monarch. But I think that new, good, solid, quality variable scopes generally START at about $200, and there really is no need to spend more than $600.
However, as a Moderator, I realize that sometimes people can't, or just really don't want to, spend that kind of money. As such, I try to aquaint myself with the lower priced scopes so that I can at least provide some guidance to economy minded hunters. Meaning the $150 scope bunch. Below that, I really can't, in good conscious and experience, recommend scopes under $100.
Now, that $10 scope you're talking about. Maybe it was a $1,000 scope new and someone doesn't know its value and is selling it for $10. OR, maybe it was $10 new and he is selling it for the same price.
I really don't know what to tell you other than chances are that you are going to have problems with that scope. Then again, for $10, you really have little to lose - other than perhaps time, ammo, and range fees.
Zachary