>>20498833I bought mine from realhotstuff and got it about a week later.
>>20491653You'll have to buy a legit 5th gen cart, but you can always buy it used.
Using a second DS or 3DS you can simply trade between the rom and the cart.
Using only one DS (phat or Lite only, DSi and 3DS won't work for this), you'll need a ROM to rip/overwrite DS saves. (You'll need one that can save to DS carts that use IR. It's by either Rudolph or Pokedoc, but I'm too lazy to look it up right now.) This is a little riskier, but you can transfer a lot more Pokemon to the cart in a shorter time period this way.