Source for high quality satellite imaginery?

I'd like to monitor progress of some local construction project, which is handled opaquely and very much along the familiar lines of political corruption.

As access to the site is obviously not possible, I thought, I could buy some sat images and make some visualizations over time. The question now is: where can I buy such images without breaking the bank (including relatively recent ones)? Maybe someone has encountered a similar question already and know some good sources.