Way cheaper on a crusie to get all meals included. Try and find a same price per day for a benefit by benefit equal land cruise. They don't exist. You are getting free meals because most people on ships make up for it with buying alcohol and other high margin vacation purchases.
Especially if you live near a big cruise ship port, you can get last minute deals on 7 day cruises for a couple hundred bucks. You have to be flexible, but it can be ridiculously inexpensive.