Hi there, KACCPA.
Thanks for reaching out here in the Community. I'd like to provide some info regarding your question about wholesale billing and discounts.
According to the Wholesale Discount Program policy, while you can assume billing responsibility for an existing direct-billed client at a later date, after November 1, 2018, you can't apply the wholesale discount price for the client. Your client's subscription will continue to be billed at the list price even if you take billing responsibility for it.
I recommend checking out the following link for more info on the discount policy.
I'm only a comment or post away if you have any other questions.