>>1168470>>1168464sorry I should add one thing - with used, you would want to factor in the cost of a store tuneup, and possibly replacing parts (small or large)
a full overhaul at a good shop could run upwards of $150 to service the hubs, repack bearings, and replace cable housing, but for little things (adjust brake or derailleur for example) it would be fairly inexpensive. if the photos are good /n/ could probably give you a rough sense of condition and how much work you're likely to need
in general, if you're looking at a barely used hybrid less than 10 years old (those are quite common in most areas), the issues you'll deal with are:
1. owner has a ridiculously inflated idea of what it's worth (you need to negotiate him down by a lot)
2. tires are probably knobbies because neophytes think they need that and manufacturers know it will sell (throwing on some slicks will be an instant and very nice upgrade, but by no means necessary)
3. everything is a little bit out of alignment and maybe needs lube (assuming it was stored indoors and never touched for most of its life). this is a cheap and easy fix at a shop
if you find something where the owner has added something like a rack, fenders, or swapped out a user interface like pedals or whatever, I see that as a good sign because it means it was used by someone with a modicum of mechanical awareness, which is a sort of ethical benchmark for a seller. they will probably have a more realistic idea of what the bike is worth compared to some schmuck who wants to sell you a 10 year old bike that cost $600 for $450, so it's just a lower stress transaction all around