Considering that the Zekrom can hardly be sold for around 10PC and the Dratini for 2PC, asking for something almost three hundred times worth what you are offering in exchange is really a horrible deal! My advice is that you collect as many Pokemon as you can and put them up for sale in the Nookling Junction for reasonable prices and hope you get enough PC to get the eshop card! Or, you can just offer something of equal value for it like a 20$ Steam card or something along those lines!
PS: Sorry Windy for discouraging, but we at least need to explain a little about how these things work, no hard feelings, right?