I can't speak specifically for Porsche leases new or used but.........
Generally speaking, leasing is not a wise financial move unless you can write it off in a business. Basically, you're paying interest / usage fees on the leased value of the vehicle as well as for wear, tear, and depreciation during time you'll have it. As well, you're paying interest on residual value of the vehicle since the entire amount of principal (total cost of vehicle) is tied up while you lease it.
Furthermore, some states treat leases differently w/ surcharges, etc. w/ regards to sales tax. In PA, it's an extra 3% (on top of either 6% or 7% depending on where you live). PA 'feels' you're denying them the entire sales tax amount they would otherwise get on the full value of the vehicle if you bought it outright. TX makes you pay sales tax on the entire value of the vehicle (capitalized cost) - basically treating it as though you bought it regardless of lease term.
At the end of a lease you have nothing to show for all you're payments. Any improvements/mods/etc. must be removed as vehicle needs to be returned to stock as it was given to you
Again, unless you can write off the cost of the lease as a business expense, most of the time (like 98% +), it does not make sense to lease as opposed to buying and financing. Of course there are some exceptions where the leases are subsidized by the mfg (or financing arm of the) - BMW is known to do this.
There are some online lease vs buy calculators to show you the difference if you leased or bought and financed a said vehicle.