No - invoice is supposed to be the "cost" of the car to the dealership, which it usually isn't. Even if it were, the dealership gets money from other incentives, like volume incentives, financing, etc so even if you were to buy a car at "invoice", the dealership is still making money.
An example: the tech package's MSRP might be 3K, but the cost from BMW to the dealership is really like 2.4K. That applies to everything from the base price to every option/package.
So if someone says "I got a 2009 for invoice", they're saying the sticker was (example) $70K but the actual invoice (cost) was $62K so I got it for that".
To figure out what the real invoice is, there's a bunch of good sites like edmunds.com which can show you what the invoice is for each option that you want on your car.