The excursions range based upon several factors especially if they include food. The Osaka excursion just mentioned lists at $124.30 per person but by watching for sales, I was able to get the excursion at $87 per person. Most ports have an under $100 option but the longer excursions are around $150 to $200 if you want local food.
We do have an excursion for every port simply to hit the highlights quickly but many people say the locations do have excellent transportation if you want to explore on your own.