I live in Toronto, Canada, and the biggest store has 1st get 2 boxes of the current set, with usually 24ish ppl playing. The one I go to most was smaller groups, usually 8-12 ppl, and approx 1 box of prizing for 1st. For the smaller stores Id see top 4 gettting at least something, and the biggest store giving prizing to top 8.
EDIT: I forgot to mention that stores here give OTS packs with your entry, usually 2-4 packs depending on how generous they feel lol