within each member or prospect profile there should be a section to enter items that would calculate the cost per unit for for prospects (trial members) and existing members with a report attached to that section. for example: I would like to keep track of how much i pay in costs (material, direct labor, shipping, referral fees) for each trial member i get in. The total sale of the trial ($1-$69) Material like free uniform, gloves, thank you cards, print material, water etc). Direct Labor the amount it costs to have staff on the floor during their trial based on classes they attended). Referral Fee if one was paid out ($50-$25).
It could be the same for members where we could categorize things similar to above over the life of the membership.