Everything can be bought at Radio Shack for about $30 except the speaker and MP3 player which is the biggest expense. You can get speakers at Radio shack from anywhere from $20 to $80, depending on what you want but as in the link I opted for the Speco SPC-5 PA speakers which I searched and found on the net. Think I paid sabout $20 each for the three I bought. I had a couple of MP3 players already so no problem there. The large drink mug I used was picked up at WalMart for $4.00. You will have to play with the little amp from Radio Shack to get the right volume without distortion and then super glue the volume control in place so it doesn't move. Control the volume after that with the MP3 player. I didn't use the red light indicator on the mug rig I made as the author in the link did. First one I made I didn't even use a mug, just the MP3 player and amp strapped together and a speaker ran out to 50 feet. WalMart sells the Johnny Stewart speaker cable extensions which are thin wire and in 50 foot lengths. Two of those rolled up will give you 100 feet and is about the size of a soft ball so everything can be put in your coat pocket except for the speaker. Set out some crow decoys with the speaker next to them and get back 50 feet or so and watch the crows come in. They are going to key in on the decoys at first but as they get closer they look for the sound so you don't want the speaker close to you. I've used this same set up for coyotes and it works great. I'd love to have one of those $500+ remote controlled rigs they sell now days but just can't see paying that much for one. So all in all each one cost me $40-$45 not counting the MP3 player. BTW, the MP3 players I used were the little cheap ones from WalMart.