Merging to unique PDFs from InDesign without any modifications to the software and using dialog boxes alone... no.
There are workarounds and other tricks. Here are three links to articles written about the issue:
However, if I was the printer and I'd received 70-800 separate PDF files to print, I'd be less than impressed... I'd prefer ONE file to print that would yield the 70-800 individual results.
If got 700-800 individual PDFs I'd be inclined to merge them back to 1 pdf.
You really need to check with your print shop(s) as to what way they want to receive the files.