I am in the same boat - have an Epson for cheap everyday printing with those ink bottles, but need a duplex scanner. I tried the HP OJ 925 but the scans come out skewed, it’s a known issue with HP and manifests in the new ‘+’ models too. Not looking to spend much, around £150 mark max and I was tempted to just rebut the OJ 925 when it was around that price last month…
I've got the (presumably older) MFC-L2700DW and that's been fine. Brother lasers tend to have toner and drums as separate units so toners can be very cheap indeed if using compatibles but you'll need to factor in a drum replacement every so often - again usually available as a compatible. MFC in the model name means this has fax function as well as print/scan/copy. The DN suffix means duplexing (usually print-only) and with wired network. Duplex scanning tends to only be found on much more expensive models and I'd be all over this if it had it but it doesn't.
Ethernet specs for this are 10Base-T/100Base-TX. The DN suffix usually means duplex plus a networking port (ethernet).
Seems a reasonable price for a laser, although worth noting doesn't have wi-fi, and neither have I seen any Ethernet interface specs (assuming for the moment t hasn't got one but happy to be corrected!) third party toner cartridges don't seem "deadly" and laser printers don't "dry out" like inkjets - running costs are usually far lower over an extended period of time. Wouldn't be my first choice, but not a bad second one and really useful if you occasionally need to print larger volumes of monochrome documents.