Porsche is expensive to maintain as compare to other cars. And cayman and boxter is slightly more expensive than cayene. However there are good porsche experts in town that you can visit and see which you like in terms of price and workmanship.
Buying from automall is not a good idea if you have time in hand, then i suggest buying from real owners who has fsh with al nabooda. Automall cost 10-20% more than secondary market.