What makes a horse more expensive?

I'm selling Painter and getting new horse, which means my parents lose out on a LOT of money. I was showing my dad some classifieds ads, and he doesn't get why one horse that jumps courses is $25,000, and another is $2,000. He is convinced that they can do the same thing so they should be the same price! (And he's and experienced horse person) Can you guys help me make a list of what makes a horse more expensive then another?

Experience
Age
Breeding
Registered/not registered
Training
Location
Show experience
How well it does at shows
What level of showing (a 4-h horse and an 'A' horse are not the same)
Who is selling (the right connections can greatly increase price)
Height
Color
Movement
Form over jumps
Temperment
Health
And?...

I show "performance horses" and actually think that a quarter of a million dollars is a fair sum of money for a good horse. What make a performance horse like this different from your every day average horse can basically be accounted to breeding and registrations/branding, level of training with respect to how old the horse is, temperment/suitability for the sport/rider, soundness and where/what they have shown and how well they've done.
So, in context a horse that's going to sell for $250,000 is one that is well bred and registered/branded, if it's a stallion has proven offspring and has done well himself in inspections, must be under 10 and jumping 1.50m or doing PSG or above WELL in international competitions, if it is suited for a professional it's going to have ability to perform at a higher level and if it's suitable for a junior/amatuer it's probably maxed out, but can pack someone aroung the ring and a MUST is that it is sound (if it's not sound the horse is worth like, $25,000-50,000 TOP).
For a $10,000 horse you are basically looking at a horse with a severe conformation flaw, OK breeding, cannot be registered except for with CW or some other joke of a breed registry, very young (3-4), possibly started,and is probably showing a behavioral problem.

Wow! $10,000 is prety much around what we want, and that should get a nice quality horse that can place in occasional 'B' shows, can jump courses just needs some finishing. I don't need/want a horse that will win everything or jump big, as long it is sensitive on the flat and can jump, I'm good