Because

In the right context, yes.

"I didn't buy it because it was so expensive; expense had nothing to do with it; I didn't buy it because it was ugly."

(That's a native speaker's opinion, only.  I don't know how to support that opinion on a grammatical basis.)

Sam C wrote:

my reason for buying it was not that it was expensive (although it was), but some other reason.

Yes, that would be possible in the context where the thing was, in fact, bought.  But it would not be possible in the context where the thing was not bought.

Diamondrg wrote:

well, davkett thank you for answering. then, is it possible to interprete the same sentence as: "I didn't buy it because of its expensiveness."? If yes, which would cometo your mind first? That I didn't buy it because of its expensiveness or because of something else?

Without context, the meaning that would come most easily to mind is--  "I didn't buy it, and the reason I didn't is that it was too expensive."