This is one of those wonderful lucky moments, that I also had.
I bought a whole load of horse manure (for symbolic 1$) - about 3x1.1,5m and more than 500kg. At first I thought - well, I can get it to compost... but as I was trying to get rid of the last 50kg (not saying about other 700), I said "no more" to good deals like this...
