「それぐらいのこと気にすんな。このまますぐ帰るのもなんだし。飯でも奢ってやろうか」
What exactly is the meaning here? He's telling the other person "Don't worry about this much" and the then "let me at least offer you lunch?"
このまますぐ帰る is "like this you'll go home immediately". What nuance does のもなんだし provide?
It's not ものだ given that it's のもなんだ, so?
For context, they were going to visit someone but it turns out he wasn't home. So the narrator apologizes for wasting his friend's time and tells him this.