1) Read about the plugin at https://scientificdiets.com/ so you know exactly what you're getting.
2) Play around with the FREE version to know exactly what you're getting: https://wordpress.org/plugins/the-scientific-diet-selector-free/
3) Then proceed here to buy!
This is a limited lifetime deal for The Scientific Diet Selector: $199.
The lifetime licence includes all features on any number of sites you personally own.*
Buy once, use forever, whenever, wherever.
Get it now and you'll get an instant email with the licence code. Enter the code in the plugin settings and enjoy customizing the plugin to your liking!
* The licence includes unlimited use on your own sites, not on sites you build for e.g. clients.
For API limitations and abuse statements, read https://scientificdiets.com/terms https://scientificdiets.com/diets-api-terms-and-conditions/
A lifetime premium licence for The Scientific Diet Selector, including all future features and diet database upgrades.