"Dlaczego sprzedają tę lampę?"

Translation: Why are they selling this lamp?

[cosmicstresshead]

They used their third wish to set the genie free and now it's just a lamp but they need the money

[JACOBhH]

I have never seen a person selling a lamp

[Wacek8]

Why is it te lampe and not ta lampe?

[Jellei]

Accusative form of "ta" is "tę", despite many natives using "tą".

It's very easy to remember actually: tę lampę (Accusative) vs tą lampą (Instrumental).