I agree that this increase is insane, but there are alternatives. As stated by a couple of you, larger or bulk orders are the way to go - a small Flat Rate box has gone from $17 to $23 (40% increase.) While this is a high increase, it isn't too unmanageable - it's $6 or about £4. I think most things purchased will fit into a smaller box (Medium Flat Rate is where the real craziness kicks in - $60!)
Also, for you in the US shipping out to, well, anywhere, you can either use Stamps.com ($15 per month, can be a pain to use sometimes) or Paypal's Ship Now page (
https://www.paypal.com/shipnow). Note that you'll have to sign into Paypal first, then follow that link, otherwise you can't get to it easily. The best thing is that it's free!
The great thing about Ship Now is that you can 1) Print your label; 2) Buy your label using Paypal; 3) Fill out customs info on that label; 4) Bypass the line at the post office and not have to deal with postal employees.
I use it all the time, and it saves a ton of time.
That being said, this BS price increase is going to hurt, and Congress needs to pull that funding stick out of its collective ass, but that is a different conversation altogether.
Now it's just if you are in the same state ... 
