Would you heavily modify Spark, or, Roll your Own?

We have a need for features Spark doesnt offer, like:

Not attaching Payment Details to a User

Not attaching Team levels to a User

Using Custom Team Levels for Subscriptions setup by Team admins

Allowing Members of Teams without subscriptions, yet tracking a members active subscription status

Allowing Teams to manage Offline Payments for Invoices

Allowing Teams to create sub-teams, and manage billing subscription plans

Spark can do it all except attaching a TEAM level to a User's CC; but when we want to extend into other areas, it starts becoming convoluted.

So my question is.. Would you User Spark,. make CustomSparkClasses that extend spark, and do what you can to allow offline payments, etc,

OR

Just make your own?

I know we can always purchase spark then rob the code examples / fork it; etc.

That $99-300 is not an issue. I dont want to waste money on MVP dev if we can extend it, but if you guys think it will be a nightmare to extend it, then its likely worth the 40-80 hours to build/clone a lot of this functionality into our own app.