I know there's already integration for iMaqma Helpdesk, however I don't see an option for their to be a subscription based on per ticket.
1. Client pays per ticket or for a set of tickets, upgrades, and also expiration for the individual tickets bought.
Example: A client can pay $90 for a single ticket or $300 for 4 tickets. Also, client can upgrade before 90 days to receive a 30% discount. Tickets last for 2 years then expire.
3. When tickets expire, they no longer have access to submit a new ticket but can still view previous tickets.
4. Tickets can be based on a subscription.
Example: 3 Tickets per month for $275. If client runs out of tickets then they can add additional tickets for $90 each.