It does not have to be though.
that was just one example,
you could just use a receiver from a garage door, but you can buy one for less then 60 bucks new (like the one below 42.90). remote less then $20.
http://www.allsecurityequipment.com/...FeYWMgodrwMAtw
use a cheap wireless ip camera to monitor the trap (50-100 bucks) take your pick.
then theres even free software that can monitor and notify you of action.
http://www.ispyconnect.com/features.aspx#home
decent sized 12v battery,solar charger ($$$ ?, lots of options)
Door pop (20 bucks)
http://www.ebay.com/itm/like/261289051141?lpid=82
Unless you plan on always being within remote range need a way to be able to trigger all that...
thinking you could modify the a remote, rather then a push button for a switch you attach wire leads, attach to a relay, something like this
http://sigma-shop.com/product.php?ProductID=7 (USB Relay, 20 British pounds, not sure on conversion rate)
of coarse you can have a second with push button also.
tie that together with a internet connection and a smart phone would work like the one in the video.
assuming you got a PC,the Internet connection,a smart phone,talking less then 250. bucks for that rig, less the battery and solar charger. you might not even need a charger? bet a little shopping and you can save 50 bucks off that figure.
So less then 300 bucks total package is my est.