Should we migrate away?

We love apex and want to stick with it but have been running up against issues. I've outlined them below, please let me know if you think Apex is the right solution for us at the moment or if it makes sense for us to migrate away from it.

**Background**
Our product is a browser extension that executes on web pages we don't control. Consequently, we log relatively large payloads to get a better idea of what was happening in the browser when the log was issued.

**Problems we've faced**
We initially saw exceptions thrown when our message strings exceeded the limit in structured data mode (#4 - thanks for your help with that). We created a new project in plain-text mode, and now the apex web interfaces freezes often. We often have to refresh the page to several times before a query produces data. We were also billed for $488 in charges last month for "BigQuery Analysis" (see screenshot below). This doesn't seem expected.

**Conclusion**
Given our use case, is it possible to run apex at low cost and with good performance?

Thanks in advance!

======================================================