First Watt F3 - Remote On/Off

You can get a Furman PowerPort on ebay for $100-150. I think they are discontinued, but are cheaper used than the newer $250 Furman MiniPort. There are a couple ways you can use the PowerPort to automatically turn on the amp. You can use 12V preamp trigger or use an external switch to power on/off the PowerPort (the switch just connects two wires that are wired into the "+12V" and "REM" connections on the back of the PowerPort). Alternatively, you could get a Furman RS-1 or RS-2 remote switch (same thing as a basic switch).

Alternatively, you could get a Belkin power conditioner that has a front-switch that turns on/off several of the A/C ports on the back. It includes a set of high-current outlets for amps. I got a used $99 Belkin PF31 (AV11) for my computer audio system and it works great as a master switch to power on my studio monitors and stereo line mixer. I think there are other power conditioners that have a front switch, but they are more expensive (which is fine if you want to spend the money on a better power conditioner).