i had also much of every other artifact when i got 3rd city and now i have about 70 -80 of every other atrifact for the 4rth city but i dont want to pay so i just keep on attacking3 weeks 10 generals each city, tried every method that worked for others in my alliance and not even close to getting a blueprint, i have had over 100++ of each other artifact... great for food boosts but a complete waste of my time. Now that the 4th city is released they should open up the 3rd city because it is a huge advantage to players that got lucky with both the 3rd and 4th city. Anyone who is willing to pay 350 game cash is either rich or stupid, rediculous amount of money.
Most kabam games are clones with different graphics, and they all require farming for new cities/outposts/whatever. Deal with it, pay or leave is the only answer :/
YOU ARE ALL WRONG!!! There is a third city blueprint that you CAN get from attacking Lv. 1 TC's. Most of you are saying that it doesn't exist simply because you can't get it. Just keep trying, be patient.