Oh look, another person wondering when to hand over the keys to the ad account. Classic.
The real answer? it's not about the budget - it's about whether you've got the in-house patience, skills, and cash to actually make it profitable yourself. most businesses flunk that test immediately. So you either sit out the ads game or hire a freelancer/agency. Both options are fine, neither has to be permanent.
Someone in the thread mentioned 10-12 hours of work a week for a $1,500/month retainer. That's borderline criminal unless you're dealing with a client who wants to micromanage every single pixel. If you're that client, congrats - you're paying for your own handholding.
For a niche like law, which is basically the Shark Tank of competitive industries, trying to DIY ads is like turning up to a fencing match with a butter knife. You'll get carved up. If you can't afford a decent media buyer plus the ad spend to test for a couple months, go scrappy. facebook groups, free workshops, giving advice - build a pipeline through sheer grit and personality.
If you happen to be a charismatic attorney who could sell ice to Eskimos, maybe you'll find a rare freelancer willing to work on a per-lead basis. Good luck finding that unicorn, though.
Here's a smarter move: spend a few hundred quid on an hourly consultant who'll audit your market and accounts. Find out if $1,500/month is even viable where you are. I'm one of those weirdos who occasionally helps for free on here (don't abuse it), so if you want a no-bullshit take on your local numbers, drop me a shout.