Say you bought a nice suit. Can you say shechechiyanu on it if there's a possibility that you might return it. If you already did say shechichiyanu on it, are you allowed to return it?
The custom is (for Ashkanazim) that a shecheyanu is not made during the three weeks. See Siman 223 Sif 3 where you see that for "celim chadashim" (new vessels) a shecheyanu is made; in practice, ...
When you purchase a new car you would make a Shehechiyanu. Would you also make a Shehechiyanu if you leased a new car?