I've got about 400k in my nation so far. It's really a great game. I have been able to fill up the large maps about 1/3 before I just can't take the slowness anymore and build an adjacent city. In case anyone is wondering, the secret is to lower funding for buildings. Ex: Build lots of schools, but only fund them as much as necessary. If you only have 200 students going to the HS, only fund it for 300 students or so (to allow for expansion). That saves a TON of money. The same works with hospitals and stuff too. Also, build lots of connections. The only thing that I don't understand is how someone can afford a stupid Fusion Power Plant. 10k/month!!! I have been able to squeek an extra 3k/month max, but that's it. By the time your city gets large enough to afford a fusion power plant, you are going to need 2 of them! That's about the only item that I havn't used yet.