You have to remember that you are talking about peak power, power usage depends on CPU usage rate, your laptop won't use 5.5 amps continuously. Things like burning CD/DVD, huge data set manipulation etc will have a high power usage. We use 150 watts units for work all the time and they never run out. I can plug my dead flat laptop in, boot it up, and use it to download big [but simple] data files from loggers [try a weather station with approx 10 parameters logged every 10 minutes for two months] and it does it easily.
I'm with Adriano and co, you will be fine with the $48 special.