Question for sellers about offers!

As a seller, if you receive an offer do you always respond (decline/counter) or will you ignore it completely if you don't want to accept?

I ask because I sent an offer when I bundled 2 items. Both items were listed at $25 each totaling $50 and I sent an offer for $40. I usually expect the seller to either accept, decline, or counter so I know where I stand and if I should just purchase the item at cost. My offer expired so I sent a message to the seller asking if they would do $40 for the bundle but still no reply. Should I just go ahead and buy the items? It's definitely not an old listing because they just posted a bunch of stuff in the last couple days. I was just hoping for some communication! I didn't think my offer was bad, it wasnt the lowest I could go it was only about 20% off.

Just curious what you do as sellers and am I expecting too much?