I have to paint the shed I just built. It’s 16 feet by 12 feet and about 7 feet high at the eaves. I’m wondering:

1. Should I invest in a paint sprayer? Is it worth the expense ($150) and hassle of cleaning, etc.? I wonder if it will increase the likelihood that I repaint the shed every few years like I should.
2. Shouldn’t paint the trim or the walls first? Why?
3. Anyone want to come help me?