Dont spend the money on that, the thing about getting abs (toned core blah blah) is that you cannot reduce fat on one spot of your body. You could do 100's of situps a day and never see your abs because they are covered by a layer of sub cutaneous fat.
The best thing you can do is use the money to buy a swiss ball and some adjustable dumbells, or a gym membership. Take some time to have a look around to forum and get some answers on any other questions you have.
welcome to the forum any questions just ask, we are a likable bunch