Kokopo is the new town built after Rabaul was buried in ash in 1994, although I believe there are some businesses operating in Rabaul again. I stayed in Kokopo for 3 nights on my way to Buka. I really only had two whole days there, and on those days I visited town and did some shopping (where I was staying was a little bit out of town).
The food shops in Kokopo were brilliant. The best I've seen in PNG so far. They had a lot of products on the shelves that we can buy in
I also went to the second hand clothes store and bought more clothes for me to wear while I am at Buka. I realised that I didn't really have very much with me. I am really happy with the two skirts I got and I think I will be keeping them for a while.