Unless someone willing to donate and send you one for free, don't mean to rain your parade, I'm afraid your expectation on the price is too low even for a really old, used but working scope.
Just google around, I believe you will find even a totally broken or not working properly scope, or worst sometimes only certain important parts might cost near or more than $50.
Especially if the scope originated from outside India or from different continent, I really doubt with that budget will be enough to cover even the shipping cost, especially the old one, this thing is usually very fragile, big & heavy and needs "serious packaging" and handling before shipping it out.
Agree with above vk6zgo's suggestion, with that budget, its better and "more realistic "for you to look for "loaner" locally.