Once you get the island it is SO easy to make money!!
I didn't read through the entire thread, so sorry if someone already mentioned this, but you can steal fruit and flowers from the games you play on the island. Just remember to put them in your basket like you would any other item you got on the island, and it'll be there when you return to your town!
My 3DS code is 2406-6551-3969 - Carly if anyone wants to add me. I usually have my gates open if I'm not visiting another town, feel free to take any fruit you see, I have just about all of it :3 I'm gonna go through and add people who posted their codes in a bit. I love visiting others' towns :D