Not sure if you can get them cheaper than this, but still cheaper than back in the day when they cost £20:

http://www.ebay.co.uk/itm/Ripmax-Failsa ... _500wt_922

This is the type I use when needed. I think you just turn the transmitter and receiver on, make sure the channel you want to failsafe is set in the position you want it to failsafe to, press a button and that's it stored.