Could i suggest to make more options for guild building cooldown:

- 400-500% the cost of "normal building" for INSTANT BUILT!
- Allow the use of voucher for building cooldown (since voucher are well known for very limited usage)

Note:
After the patch Lv 9 - > 10 takes : 1,024 hours / 42.67 days.
The waiting is enough to drive all the members crazy, having to wait 1.5month for 1 new building