You're probably asking.. How is this possible?
Guild Perk at Level 24
This perk is obtainable once your guild reaches level 24. Most guilds are 17-18 right now ( well ones that hit the XP cap everyday ) so you should be getting this perk fairly soon. It reduces the cost of vendor items by 10%, saving your a grand total of 1.25k off the chopper parts.
This is by far the best method to use when crafting Choppers. Goblins receive a 20% discount from any faction regardless of reputation. Using this will save you 2.5k. This is mostly available to people who play horde side, but people who are alliance based can ask people in trade chat to go out and buy the parts ( make sure their guild is level 23 once it's available ), say you're tipping them 500-1,000g for their troubles and I'm sure you'd be able to find someone that is willing to do it.
Why craft choppers at all?
Wrath materials are now starting to ( or already have ) inflated. I've seen choppers sell for as much as 15-16k, and trust me; they sell. If you're able to craft a chopper for 30% less, you're going to be saving all that gold instead of giving it to a vendor. With a 30% discount you can craft choppers for as cheap as 8.75k. You can craft a chopper for a grand total for ~9.2k and then sell it for 14-15k and make 6k+ per chopper you craft.
I've personally made roughly 6 choppers this cheap and I sold them all within 24 hours of them being crafted. I gained a total profit of 32,000g. I spent a grand total of 55k and sold them all for 87k ( 14.5k Each ). It's great gold if you ask me.
Will you be crafting any choppers soon?