I highly doubt that you will get 500 syncs, considering the new pricing plans that just went into effect. Airtable only offers a maximum of 20 synced tables per base, so if you were already at 100, that’s already 5x over the limit.
More importantly, though: Why do you need 500 syncs? What sort of an app are you building? Airtable was definitely not designed for this sort of a setup, and this also doesn’t sound like very good database design, since you have so many duplicate databases.
Are you trying to build a customer portal? If so, then you should be using one of the many portals that are available for Airtable, such as Noloco, Softr, JetAdmin, or Glide.
I give a step-by-step tutorial of Noloco on this episode of the BuiltOnAir podcast.
And I also presented a full one-hour webinar on Noloco called Building a Client Portal on Noloco powered by Airtable.
p.s. It sounds like you would greatly benefit from working with an expert Airtable consultant who can guide you in the right direction here. If you have a budget for your project and you’d like to hire an expert Airtable consultant to help you with any of this, please feel free to contact me through my website: Airtable consulting — ScottWorld