Some suggestions
Affordability
Bronze version - ad free - $20 a year
Bronze version duo - two users that share same meals all the time - $30 a year
Silver version - bronze plus recipe import, timestamps, share custom foods and recipes - $ 50 a year
Silver version duo - two users that share same meals all the time - $75 a year
Gold version duo - two users that share same meals all the time - $100 a year
Usability
Duo version would allow duplication of all meals automatically for both users, speeding up data entry for couples. Individual food items could be deleted for added for one person to cater for omissions and extras