For starters I live in the US (currently in CA, used to live in NY State and hoping to move back). I try and attend tournaments on a bi-weekly or weekly basis (but this is hard where I'm currently living and due to looking for work, and my schedule having out of state interviews in it to work around).
I think this depends entirely on how often the organizer runs tournaments, if you run a weekly Legacy/Vintage tournament then I would expect entry fees to be closer to $5 - $10 (as over milking the cow is problematic, but having a weekly tournament keeps the customers in your store week in and week out) with lower prizes (packs or store credit).
If you run your tournaments on a monthly basis, I think $15 - $20 is acceptable with "money cards" as prize support. I don't ever think prizes should be first place and nothing else, but I'm also not a fan of some stores/organizers policies of "every one gets a pack/prize for playing!" Having it first place only discourages decent but not great players from showing up, while having a "no one leaves empty handed" event discourages better players from participating because the pay out for the prize cut offs becomes far less.
I think we've (Americans) come to expect that if its a Power 9 tournament or there's a Lotus for first place that the entry fee will be $30. If it's a Mox Tournament, I think we've come to expect $20 as an entry fee, or if its say a Mox for first, and Workshop for second, Grim for 3rd, and Drain for 4th to have something like a $25 entry fee, or a $20 entry fee with a larger field (at a large store with a great facility knowing that they can get the numbers to show up).
I'd rather see the prize support for the top 8 be closer to say a 25% for first, 17% for second, 12.5% each 3rd and 4th (you get half of what first gets), 8.25% each for 4th - 8th (First here is getting essentially the same percentage as they would at a SCG P9 tournaments).
Comparing this to the recent Eudemonia Lotus tournament, First was a lotus, 2nd was a Library, 3rd and 4th were Drains, 4th - 8th was choice of 2 Scrublands, Badlands, Savannahs, Plateaus (with each player afterwards picking what's left over). $600 first place prize as compared to the rest of the top 8 for a $30 entry fee is a huge disparity. This roughly breaks down to 1st getting 60%, 2nd getting 12.5%, 3rd and 4th with 9% each, and 4th - 8th getting a mere
3% each (I'm using rough eBay prices for determining the value of the card).
I think this thread might benefit from some more conversation about percentages to address the 1st vs. 8th prize support. I realize many organizers can't put up what the entire prize support is up front before they know how many people are physically at the tournament, but I don't think that's an excuse for making the prize support essentially be break even for 4th - 8th when you have 50ish players paying $30 each.
Again, the price of entry is going to be roughly dependant on how frequently you hold tournaments, and then your prize support dependant on how much revenue you bring in. I prefer seeing TO's be either completely upfront with guarenteed prizes, or be upfrount and say if W people show up, the prizes are X, and if Y people show up, the prizes are Z.
EDIT:
Door prizes are also awesome, and should be encouraged, as well things like top unpowered player, top junior and any other cool prize you can think of (Ray has great prizes at Waterbury, and there are some great ideas that can be swiped from his tournament threads).
I completely agree with this, however, the largest door prize shouldn't overshadow 3rd - 8th place (as it did at the Eudemonia Lotus Tournament). I picked up a Juzam Djinn for winning the 6th round door prize... hm, looks like I made out better than 6th, 7th, and 8th combined...