Cody,
You could also use a middleware application like Hightouch that uses SQL as a source and HubSpot as a destination. If you can constrain the sync requirements the monthly cost is competitive and the infrastructure is already there so overall costs would be lower than doing it custom.
For what it’s worth, Datawarehouse.io offers a HubSpot-SQL connector that is one way from HubSpot to SQL in case that also has utility for you: HubSpot Marketplace