For some reasons I could not buy 1st upgrade on my brand new account (2 games played). Every time I clicked on the button it took shards from me but didn't give me upgrade. I played a game to earn more shards and bought 2nd and 3rd without any problem. Sadly I could not test 1st as I was out of shards. After one more - longer game - I've tried to buy 1st upgrade and it worked just fine as well as 4th.
I've created new account yet again and now it worked perfectly to buy 1st upgrade. I've experienced some rare glitch or something? Lets hope it does not happen for casual players with normal prices.
BTW:
"+10% of map region count" could make it more clear. At first I thought It depends on region count owned by me - so if I have 40 regions I get +4 and if I manage to claim 60 regions it increased to +6, etc.
Also... Do 3rd and 4th upgrade "stack"? I mean... On map with 36 regions will I get +6 (2x10%) or + 7 (20%)?