You get what you pay for...
When I was 4-Her, open shows were about $4-6/class. Since they were one day deals, there were no stall fees. The State 4-H show was the expensive one at $20/class and $25 stalls for the weekend. You were limited to four classes (Showmanship, Equitation, Pleasure, and Trail). That was a big deal for my family, and we saved up to go.
When I was in college and we started showing the minis, the breed show classes were $25 each and the stalls were more. I thought that was outrageous. So when we watched our first ADS show, I was sure that they would be more than $25 because they were so much more elegant than the breed shows around here. I was blown away to find out that they were only $10/class! Stalls are about $90-100, but around here they need to rent tents and stalls because the shows are not really on "show grounds". That is one of the "draws" of carriage shows, though, the venues. We show in front of a mansion, an historic pavillion, a grounds specifically designed to host CDEs, etc. We have only been to a few that were just at a fairgrounds and the like.
Now the more I know about ADS and organizing a show, I can tell you that the entry fees don't begin to cover the costs of the show. Sponsorships are always necessary. I happen to know that one show has over 10K just in stall and tent rental. The same show has a budget of over 100K and only makes a couple of K, which is used for start up $ for the next year. The judges aren't just your everyday judges, they are licensed ADS judges who have paid to go to clinics and "jr." judge at shows with their own $$ to get licensed. They usually have to be flown in and put up in a hotel, which adds to the costs. No, judges are not going to do it for free. They need to have their costs covered and maybe make a little on the side. The carriage show ribbons aren't extravangant, but any ribbon at a carriage show is a good ribbon. Division Champion awards are more extravagant.
No, you can't make the classes cheaper and get more entries, because there are only so many daylight hours in the day, and they don't want to run cuts. You can only fit so many entries in an arena at a time, and the cut off for entries according to the Rulebook is 14 (some shows can squeeze 1-2 more in if they have room in the arena and schedule). Obstacle classes and CDEs are all individual goes, so again, there is only so much time in a weekend. I don't know of any carriage shows that are held in a lighted indoor (except the brand new CAA show in KY in July). And CDE marathons have to be outside.
Some newer shows have gone to using some ADS rules, but not getting ADS judges and TDs and running an abbreviated show on one day to save costs that way. However, I can tell you that while those shows have a place, they don't have the "prestige" (I bet there is a better word, but I can't come up with it right now). People will pay to get a more "educated" opinion. I could judge those "lesser" shows, but wouldn't you rather get Craig Kellogg's opinion over mine? Hence why ADS shows command a bigger price. Some of those shows can "evolve" into ADS shows eventually, though. A lot of driving shows have started as non-ADS shows.
This year, I have about $2500 budgeted for six carriage shows and one clinic, not including food that is not included (dinners are sometimes included in awards parties). There are usually about 6 classes in a division, so we are looking at $60 entries and $90 stalls for $150. Another show we go to is $12/class and $100 stalls, but Walnut Hill was $100 for a division of four classes plus the Presentation Pleasure Drive, and $150 stalls. You pay for prestige. We don't bowl, play sports, camp (other than at shows), go to Disney World, etc. Carriage driving is all we do, and we consider the shows our "vacations". The nice thing about carriage driving vs. other horse shows, though, is that once you have your equipment, you don't have to upgrade to "be current" (if you get good equipment to start). My 25 yr. old harness is still appropriate for showing, but my 25 yr. old saddle would be laughed at.
Myrna