[welfare]

So here's the deal; I'm thinking about picking up a new truck. My intention is to keep it for the required six months, drive it, then flog it.
The sales guy says if that's my plan, best option is long-term lease then buyout early when it's time to sell. Reason being is that I'll only be paying tax on each payment rather than the entire vehicle.
As I understand it, third party buyout relieves me of paying the tax. And if the third party is a seller with pst number, and shipping it down south, he also isn't required to pay it. That sound correct so far?
There's a $4500 rebate for leasing, which would negate the 3 $1000 payment penalty for breaking the lease.
Are there any disadvantages to achieving my objective through leasing over financing?
I've never bought, leased, or financed a new vehicle before so any advice from someone with knowledge on the subject, either through experience or someone who works a sales department, would be greatly appreciated.