Judges generally get little to no information on entries with the exception of the category where it is entered. In certain categories the entrant is REQUIRED to submit some information, but that is only in a handful of categories.
Prices can range from inexpensive to expensive for any number of reasons. Perhaps it is the only fundraiser for the club so they charge $8, perhaps the club doesn't need much money and wants to drive up entries so they charge $4. Our club would like fewer entries so we tend to charge a lower price for the first few entries and as the entry count increases so do the charges. In 2009 I think we were $6 for 1-5 entries, then it jumped to $8 for 6-9, and $10 for 10 and over. People didn't get the point so in 2010 we did $6 for 1-4 entries, then $10 for 5 and over. That left a sour taste in many people's mouth thinking we were gouging so next year we are currently discussing $4 for 1-5 entries and $15 for 6 and over. We need ~$4-$5 to break even and are trying to drop our entries from the 441 we had in 2007. We had 424 in 2008, 441 in 2009 and got back to 343 in 2010. Our goal is 300 or less and to keep the entries low we had to drop meads and ciders in 2009 and 2010 which normally brought in another 100 entries.
Back to the original question about number of entries per brewer, I am unsure why any comp other than the AHA would need more than 3 bottles. The AHA needs 1 initially and 3 later. In reality on some categories they should require 2 initially and 3 later.