@JackCoopersmith … Inventory management was #6 on my list at first but didn’t want to come off as greedy 
This would be AMAZING to have as an additional function built into HubSpot.
As for talking to other inventory management systems… I think it would be nice to have but there are so many out there. In a former role, I worked with many of the larger names but only one that truly solved the customer’s need for agility in inventory management. I think the bigger names have integrations through Zapier, so that you could be a temporary solution that allows direct bookings through established software as well as bookings/purchases through HubSpot … while still keeping up with inventory.
However, if you are looking for an in-house solution, I would be happy to put you in contact with the team I’m talking about. They are small, agile, and they are inventory management magicians! 