The best financial decision in the long term will obviously be to buy a slightly 1-2 year old Used CPO model. That's what I tried to do until I realized even 2011 535i's with M Sport Package and almost any miles were going for barely less than discounted new 2013's (in some cases, even asking more, fathom that). At the same time, I've spoiled myself in wanting the emotional-effect of a brand new car now.
One good point about Leasing is that for those who invest their cash, by way of literal investments, trading stocks, etc., you can make lots of money because you didn't sacrifice a large chunk to buy a car (or at the same time you can also risk losing money which could have been even more safely tucked into the car, to balance out the perspective, however let's stick to the making money part, as that's the plan). Therefore, even if you went into a Lease with the intent to buy after the Lease (to make the comparison fair), after all is said and done, due to the rental fees, the higher Lease-end residual value, etc., you'd be paying a good $5+K than if you would have bought the car in the first place. However, let's say we're talking a $65K car, and even saying you'd "only" be putting $30K of it down, how much is the "Lease Luxury" worth to you? I.e, how much can you make from having that extra $30K+ with you, how much do you value a 2-3 year "Rent To Own" trial? How much do you value having the ability to not have to be stuck with the resale of a car that was in an accident, if the car got in an accident during that initial "Trial Period"? Etc.
Saying that your intent is to BUY a car, and you don't want to spend over a certain amount on a car for the next 5-6 years (which would eliminate the notion of Leasing multiple cars as you'd be spending almost the price of a new F10 for a 6 year rental), you can purchase outright and avoid all the Lease fee's and high residual purchase factor, or you can Lease, and value the above prospects I listed that come with it, realizing that you will have to pay a good $5K+ for that decision, but can prolong it extend it for the entire 6 (or 8 if you really pushed it) years in this case, while choosing to pay extra to take a more "risk free trial run".
'13 F10 BMW 535i Sport
: Jet Black/Black-Anthracite : Premium & Technology Packages/Sport Auto Trans/Camera/Park Distance Control/Heated Seats/Tinted Windows/Blacked Out Markers/Performance Spoiler.
Ex M-B's: '11/'10/'06 E350's w/ AMG Sport Package, '02 S500 w/ Every Option.