They are a rip-off. That's why we don't buy them anymore. We have enough from our previous 50+ cruises which cost around $5-6 and we could buy a single picture and not some package.
Take your own camera and have someone take a couple of formal pictures for you.
The last couple of times we have been on the ships, they had a line for "picture" and another for "no picture". We thought this was great.