If you had a pc already with two NICs, you could do sophos xg home on it or a pfsense/opnsense. I’m planning on virtualizing a VM on a cheap mini ryzen box that meets that (ace magician makes one for $300).
Do you need the latest router, or just "a" router? I usually get mine for like $10 at Goodwill. They're a couple years old when I get them, but they work fine and I don't need anything fancy.
I’m not quite sure, but I think the majority of the devices in that price range, if not all, fall into that category, being made with 4MB flash memory, and 32MB RAM. OpenWRT can hardly fit into that, it’s only possible with a custom image and making compromises
I’ve been very happy with Ubiquity Edgerouters the last few years. Their ER-X model can do 1Gbps total… So if you’re downloading at 500Mbps then you can upload at 500Mbps. It come in about USD 60 I think.
Next level up is the Edgerouter Lite 3. It is much beefier and can easily handle 1Gbps both ways and even faster. It’s just under $100. 99 or so. Maybe you can find it on special.
They are really prosumer and definitely much stabler than typical consumer routers. Eg I haven’t reset mine in more than 2 years.
It’s not open source like mikrotik but they are very hacker and tech use friendly. Most things work via CLI. And most advanced router functions are supported.
A “free” option if you have some PC hardware lying around is to run OPNsense/pfSense instead of buying a dedicated box. I say “free” since it will use more power and require more time to configure and manage.
Alternnatively, I ran one of TP-Links AX consumer router/AP combos for several years and it was solid. Even had an OpenVPN server built in. I can look up the exact model if you’re interested.