Can anyone tell me how much it would be from Boston?I
Find a travel website online. It's not difficult.
Can you find a decent hotel in a major city in Poland for 150zl?
I can think of at least three places in Warsaw alone. I've stayed in one of them myself. Nothing special, but clean and definitely adequate for a few nights.
It's even easier to find cheap accommodation if you can read Polish, which means that you can use Polish booking sites instead of the international ones.