You're going to die, I can see this coming.
Edit: Let me append a bit more to this. DNP is probably the single most dangerous chemical discussed on this board. Not only has a forum member already killed himself using it a couple years back, he got his source sent to federal pound-me-in-the-ass prison for it. This last guy thought he knew his shit and even though he was young, he had used more gear than eighty percent of Elite. He kept posting here asking about the effects of his using recreational drugs and gear at the same time. He was as hardcore as you could get -- to the point of total and complete recklessness. Then he started eating DNP caps like Skittles, and the rest is history.
You're asking how to buy flammable, poisonous DNP -- a chemical that has to be shipped by poison pack -- why, exactly? You're don't know how to go about it, what it's used for, or (very likely) how to handle it responsibly. That's a recipe for disaster, and while there are many here who will help you out, I'm not one of them.
You need to realize what you're saying you want to do. You don't buy chemicals in quantities of 5 grams. What are you gonna do with the other leftover pound after you've capped your cycle? Hide it in your closet next to the furnace? Let me quote you a little bit from the safety sheet:
Health Hazard, Class III (from 4 for the greatest to 0 for the least): "Materials which on short exposure could cause serious temporary or residual injury even through prompt medical treatment was given."
Flammability Hazard, Class III (from 4 for the greatest to 0 for the least): "Liquids and solids that can be ignited under almost all ambient temperature conditions."
Reactivity Hazard, Class III (from 4 for the greatest to 0 for the least): "Materials which in themselves are capable of detonation or of explosive reaction but require a strong initiating source or which must be heated under confinement before initiation or which react explosively with water."
Having said that, try not to kill yourself. I'm saying this for the people who can't.
I suggest contacting a trusted source and going from there.