I bought a TUFFSHED.
I don't have the spare time to build a shed, I spent three weekends, several after work nights, painting and shelving it top to bottom. My sons spent plenty of hours working on it with me.
I would really recommend them. Don't buy the tuff shed from home depot or lowes...they sell for the same price but use particle board instead of plywood.
Tuffshed made the door 6'8" for me at no extra charge
I spent $500 on the wood alone for the shelving, If I bought the wood for the shed, the roofing and if I could buy the steel beams that they set the shed up on I don't think that I could make up the difference in cost.
Let alone the time to $ ratio saved.
As far as the cinder block Hell Yah!
I couldn't do it where I live...I needed a temporary shed and the city wouldn't permit the cinder block shed.
yes buy the biggest one you can ! I also bought the "tall barn" for extra space. Trust me you need every foot that you can get