I've been playing guitar for 20 years more off than on it must be said. In that time, I purchased a number of pedals at aroung £50 none of which had a power supply included.
Whether this device is as good in one area as the BOSS equivalent pedal, I don't know, but to have 54 effects for the price of 1 pedal is amazing value for money.
If, like me, you are dabbling and want a selection of pedals, then this is an ideal starter which also includes the tuner function, drum machine and mains power supply.
On a negative, if you want to get the most out of it, you are going to have to learn how to use it properly, which will take some doing. That said, you can get some interesting stuff by quickly plugging in an going.
Oh and a last point, plug in your headphones and you don't need to amp the device!