MIS60
One of the oldest Mac security companies. Available for 1 Mac or 3, 1 year or 2. Also can add Panda for your Windows computers (or Windows on your Mac).
1 year, 1 Mac = US$20
2 Year, 1 Mac = US$36
1 Year, 3 Macs = US$40
2 Year, 3 Macs = US$74
Or you could just use the free Avast (which should be good).
All of them should detect Mavericks as malware, lol.