Firewall Advice

Hello; Currently I'm using an ASA 5505 for my small business and I wanted to upgrade to something else more manageable - so I need your advice.

Needs:

Currently my setup is :

• A DMZ on a hardware interface. I expose some DMZ servers to HTTP/HTTPS for basic web server functions.
• A public subnet, which is connected to a WIFI SSID for public guests (can only access the outside).
• Using AnyConnect VPN for basic VPN'ing into the office (But any easy to use VPN will work).
• I have 7 static IP addresses
• 90% of my devices are gigabit.

I would like to know if a non-cisco device exists that compares with the ASA. I want to avoid the heavy Cisco costs - I cannot afford 500$ per year for a contract to maintain a firewall. And can't afford 500$ just for a license to connect my cell phone to anyconnect VPN. My "small" business is actually just me - money is limited.

Basically having control over subnets and linking subnets to physical ports is a nice feature for me, all suggestions are welcome! Sorry I'm not very up to date with firewalling.

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