Here’s the skinny on real estate agents:
If you’re buying: Use a buyers’ agent if you’re seeing a house listed with an agent already. If you don’t bring your own agent, the listing agent will likely offer dual agency which just means that they’re representing both parties of the sale and thus doubling down on the commission rather than splitting 50% of the gross commission with your agent if you choose to bring your own. Obviously, the sellers’ agent (who will now also be your agent) has the sole interest in the deal closing, so they’ll have very little desire to steer you in the right direction.
If it is for sale by owner, I strongly recommend going in without an agent and letting your attorneys hammer the deal out. Even though the seller conventionally pays the commission, you can get significantly better pricing due to the lack commissions being paid. Many sellers will outright refuse to pay an agents’ commission due to that theory. On a $300k sale, the agent is taking $18k conventionally, so if you buy using solely attorneys at $290k, they’ve pocketed $8k and you got a better deal. I buy investment properties this way as much as possible because the real estate industry is wildly antiquated in my opinion. The issue may be whether or not you find a seller who is competent enough to deal with a for sale by owner situation as it does take some level of familiarity with the real estate transaction process.
If you’re selling: Make at least SOME EFFORT to sell it on your own. You can always list with an agent later if you feel that will really put the listing over the top. Buy a low grade DSLR on eBay for $300-400 and Google “how to take a photograph”, push your listing to Zillow/Trulia/any other free FSBO sites, et cetera. You can always toss in a 2% or 3% commission to buyers’ agents so that they don’t intentionally steer buyers away from your listings, but that’s your jurisdiction. You may need to do this if you are selling single family properties, especially in the suburbs. My opinion is that the thousands (or tens of thousands) of dollars you could save selling it on your own is always worth the extra work unless you’ve got an eight figure plus net worth and even then, eh. It just isn’t that much harder nowadays than using an agent honestly.
That said, I have gotten some insanely good deals on investment properties by FSBO situations where the seller really didn’t understand market values or comps and I was paying 10-25% under market value, so if you plan to sell anything on your own ever, do some homework on comps. Hyper-local price/SQFT adjusted for improvements is probably the best way to value out single family homes. Multi-family and investment properties get a bit more complex, but it generally will depend on your capitalization rate as that should in theory directly correlate to price/SQFT, et cetera (but not always, I won’t go down that road at current).