So I am interested in buying a bike. My Indian friends have told me pretty adamantly that I should NOT buy a used bike as any repairs would cost nearly as much as the bike itself. Thus, I should buy a new bike. I don't get it--how can people drive around these obviously ancient bikes and scooters when it cost more to fix them than it does to buy another used one...

And how can they cost so much to buy used if they're worthless as soon as it requires any repair?
So, my question is this: Is it foolhardy to look at buying a used bike, assuming that I am willing to go through all the hoops to make sure it's a good bike before purchasing? Is there any way to purchase from a "used bike shop" and have some kind of guarantee?
Or: Are they overly concerned because I am a girl and can't handle the upkeep of a used bike or something?

Or is the fact that I am a foreigner and the assumption that I obviously have the money to invest in a new bike part of it? (Which I don't have...).
I am looking at some kind of Hero Honda, or similar, with gears, and a bike not a scooter. If I can manage to get a license, that is...
Thanks for any input! If anyone wants to come shopping with me in a couple of months, feel free to volunteer.