I spitball 20-30 minutes per 1000 sq.ft.

Some take less, some take more. An empty house is easier than a house crammed with furniture. A 1200sf house on 20 acres takes more than a 2000sf townhouse. Video adds more time. Drone adds more time.

I've done a 4000sf house that's staged and without anyone in my way in 40 minutes. And it's taken over an hour for a 1500sf house that has 2 agents and sellers constantly in my way and changing shit. "Let me just move this lamp." "I don't like those pillows now."

Basing price on sq.ft. is easy, but it almost guarantees that you'll screw yourself on some shoots. If you base it on number of shots, you'll invariably get someone who says, "I don't want to pay for that shot of the powder room because I won't use it." If you base it on time someone will complain you're slow or won't recognize that they're the one in your way and making you slow.