What is the meaning of two buts following each other?

So I’m reading tobira chapter 10 kaiwabun 1 and I came across this sentence:

確かに スーパーの方が安いかもしれないけど、でも コンビニは24時間開くいている店が多いし…

I don’t know why there’s kedo and then demo followed up in the above sentence..what does it mean?