Pricing varies based on what you're expecting to accomplish with a horse or what it's existing track record is. Horse's that have established show or breeding records would have command a higher price. If I was looking at show prospect horses and wanted to go to the Nationals and be competitive I would probably be looking at the higher end that you mentioned and the trainer, etc.
Having said that, there are wonderful great buys out there of high quality horses - but it's like going to a discount store to find the perfect suit versus hitting Nordstroms or Macys (with the expensive selection, custom tailoring, expensive ads and wonderful presentation) - you'll find it if you're willing to put in the time to search, contact lots of ranches, network, look at lots of horses, really educate your eye on horses that aren't professionally groomed or professionally fitted and be able to recognize the quality when you see it - you'll find the perfect mini or two.
Also don't be afraid to ask a ranch what they're bottom price is if you see something you'll like. Heading into Fall alot of prices get softer and many ranches list and in person price are grossly different! Another idea, if you see a horse that you're willing to promote (show heavily, advertise, etc - don't lie and be prepared to put this in a written contract!), often a ranch will be flexible on pricing as the PR helps with their overall plan, so don't be afraid to discuss these option with breeders as well.