I know there are a lot of recommendations here, but I can provide some insight as someone who has been looking into this heavily for the past several months.
I will start by saying that the GL.iNet Flint 2 running OpenWrt is probably going to be your best option. It meets your price point and concerns. The Flint 3 is an upgrade that just came out that could also be considered, but is currently at $190. I currently have the Flint 2 running at my mom’s house providing her network coverage. It’s a nice all in one device and I believe she’s running a 500Mbps service.
Some of the other responses here mention OPNSense. That’s what I’m running right now as a virtual machine. I’m using TP-Link Omada access points for Wi-Fi coverage. OPNSense or PFSense might be a bit much to start. They are good options, but can get rather advanced quickly and still require a method to provide Wi-Fi. I’d been looking at replacements heavily lately, but decided to stick with OPNSense (I just have to migrate it from running on VMware ESXi to Proxmox now).
I know the process. There’s also the option of attaching an ESXi datastore to a Proxmox system and importing it that way. The PCIe passthrough makes it a little more complex but not insurmountable. I’ve built the Proxmox server on another host with 10Gbe ports and am going to rebuild that way. Export the config, modify what I need to, import the sections I need and swap cables.
Once I’ve swapped hardware, I’m putting Proxmox on the current VMware host and I’ll have a backup system just in case of hardware failure.
I’m also doing some other stuff, replacing HAProxy with Caddy, maybe deploy a grafana dashboard so I can start monitoring all 60+ services on my network, and configure my network for IPv6.