The first thing I recommend is to contact support, explain the situation, and beg for more automation runs. Currently there is no way to purchase more automation runs. Maybe with enough people contacting support about these situations, Airtable will eventually implement some way of purchasing additional automation runs.
If you upgrade to the next service level, you can also gain automation runs that way, but that may be cost prohibitive. I mention it in case you were on the fence about upgrading and this might be the issue that pushes you to do the upgrade.
You can also see about moving some of your automations to a different platform that allows you to purchase additional automation runs, such as Make.com or Zapier.
For future planning, I recommend being very careful about configuring automations. It sounds like your automation is triggered by a record entering a view. I no longer use that automation trigger, and it exists mostly for historic reasons. You can get much the same result by using a "record meets conditions" trigger directly in the automation.
Sometimes it is also possible to consolidate automation runs by using repeating action groups and/or scripting. With a repeating action group, a single automation run can update thousands of records.
