Care / maintanence and manufacturer will play the biggest role
I would happily buy a german / japanese model with 100k + for example
what type of 2003 car are you looking at that cost 15K still?
There are a lot of variables, but most importantly, how many miles do you drive per year? If it's a lot, 110k miles is not a smart purchase. If it's not, 110k would be reasonable.
Uh, way too many variables to look at it in these simplistic terms.
I bought a 1998 pickup truck in 2001 for $20K. it had less than 100K km on it. Over the next 7 years it cost me around 8K in repairs. Lame. My current truck I purchased brand new in 2011 for $22K, and it won't cost me a penny in repairs for the duration of the warranty (5 years/120K km).
But I also had a 1990 Jeep that I paid $2K for, unknown mileage as it had a different engine put in at some point, and that thing would go forever with very little maintenance costs.
So what do you need the vehicle for? What model best serves your purposes?
Well my wife put on 1500 miles last year. No, I didn't forget a 0, it's 1500. However I'm having a third kid so I'll start to use it a little more often. My other vehicle is a car that holds 5 people though. This new one would be a SUV or minivan that doesn't get used a lot except for trips.
With that low of mileage, I would not be bothered by a vehicle over 100k.