can I have different subscription levels?

[Protect Yourself N95]

can I have different subscription levels i.e free for admin but paid subscription for sales?

[Jack Brickey]

No this is not possible. When you move to paid you must pay for all users on that instance. Now you could consider having two completely independent instances where one is free and the other not. But you can’t connect the two. 

[Iain Dooley]

@Protect Yourself N95 upgrading to Business class is done at a team level. You only pay for team members or multi-board guests, so your options are to either limit the sales team to being members of only one board, or have a separate, free team for sales and don't add the sales team to boards in the admin team.