Helped an older friend recently with issues with his antivirus. Discovered he was paying $199 per year for Trend Micro which is obviously a rip off.
Discovered Bitdefender Total Security 3 devices for 12 months code for 78% off. $19.99 (USD) which turned out to be around $31 (AUD). Need to cancel before 12 months otherwise will get charged $149.00 but pretty sure you can sort out some deal code then.
Or just use Microsoft defender and don't visit dodgy sites.