$1000 used to be the floor for bike prices, but I think it's now more like $2000. In the $2500 - $3500 bracket I'm seeing lots of uninspiring middleweight cruisers, a few mid-90's sport/touring bikes in decent condition, some newer crashed/trashed sportbikes and "the engine has a clanking noise but it should be an easy fix" bikes. Almost everything in this bracket is 10+ years old.
Any good condition starter bikes in this price range are definitely going to be 10+ or even 15+ years old. I'm seeing some CBR125s and CBR250s listed for nearly $3000, which seems like an extraordinarily high price, but maybe that's just what the spring market will bear these days.
People are weird about age and mileage on bikes. One of my bikes is almost 20 years old, has 80k+ on the odometer, and is still as reliable as the day it rolled off the assembly line. Aside from crashes, what usually kills the condition of a bike the fastest is just storing it outside, or having mice chew on the wiring, or having a series of hacked on mods. All of those are pretty easy to spot.
I started on a Ninja 500, which was one of the bikes mentioned earlier. It was a great first bike and rather peppy up above 7k rpm. The knee angle was a bit tight for me on longer rides and would probably be more of an issue for you, but that's common to most of the standard/sporty beginner bikes. Beginner bikes typically have a rather low seat height, but that reduces the seat-to-peg distance and folds your legs up more. That can be solved relatively cheaply with a taller seat and/or lower pegs.
This won't help in the conversation with your parents, unless you can use it recalibrate their opinion on the age of the GS500
:
Selling my bike, looking to get a bigger one 600~750. Had it for about 6 years or so now always stored for winter. Been dead reliable, I replaced the clutch last fall and got a new battery for it. It has new plugs, air filter and the carbs cleaned and adjusted 2 years ago. It has bar end mirrors...
www.kijiji.ca