Navionics Subscription(s)...... crazy expensive

[Gi-Lo]

So I have been using the navionics app very successfully, but now I want to try inavx..... with Navionics Charts. surely one subscription should cover both these Apps?...... it doesn't appear so, looks like I have to pay two separate subscriptions for the same charts...... furthermore, My B&G Vulcan can use Navionics charts, but it looks like this would have to be a THIRD subscription for the sane charts?...... am I missing something?...... thus seems ridiculous??