I am Gopalan Mani, more then 10 years experience with microsoft technologies and database programming.
I have read this post.
customer paid options contain some more items like gym, mma class, boxing class...... in this case we can maintain the values using "Lookup Wizard" data field features and it support many options with single field.
A lookup field can display a user friendly value that is bound to another value in the source data table or value list. For example, the lookup field can display a customer options that is bound to a respective customer option number in another table, query or list.
example, we can set any options (like gym,mma, boxing) to particular customer, but that values maintaining with single field and also that field allow unique values. and also we can add more items in any times
and also we can provide the user interface for that process using "Form".
If given a chance to work as an employee in your project I will produce positive results.