Because it is your item, when you look at it, the buy it now price is still visible.
However, when potential buyers look at your listing, they won't see a buy it now price. As advised, once a bid is made, the BIN price is no longer valid or available as an option.
You can't accept an offer - that would be unfair to your bidders.
Just tell the interested buyer to make a bid,
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)