The basic Dun & Bradstreet subscription is $50/mo, low enough that I think most just turn it on/off when they need to refresh their cached data. (i.e. turn subscription on, run api client with something like jcache enabled, set a long/infinite lifetime on the cache, hit the api with a list of 50 companies you’ll use for testing, turn off subscription)

For production, you use a subscription account, the $50/mo is worth it to have accurate/current entity data.