Step one of filling items with water when power is cut can be a useful step, the rest is nonsense.
I grew up where power cuts aren't that odd. It's really not this end of the world, everyone going looting, abandoning cars, wild west. It takes a bit more than that for most people. Some people are a little too keen to get into where they'd want to loot if they thought they could...
Also, cash registers to take cash still run on electricity. Businesses with generators are rarely going to have the staff or any desire to waste their generators selling to people grabbing things last minute when it's better used for security. Some might, but do not expect them to do so and don't expect them to sell it at a fair price in an emergency. Anything on your list that involves buying should either already done or planned to be done as soon as capable if you are a 'serious prepper' as others have mentioned. If you were really serious, concerned, and have the money to go all this in a very short amount of time when people will be price gouging - get solar panels that can be islanded off to work in a power outage. You'll still want candles and the like to be able to ration battery power if it's really bad, but as someone who lives with people who have medical equipment relying on electric, it's good peace of mind if you're in a position to do so.
Lastly, this whole 'fuck everyone else' mindset will in a long term situation make things worse for you. My first steps if I was home would be to gather the family - having a means of contact and people knowing routes home is a great step, then it would be check in with some of my neighbours. Making allies is the most essential 'prepper' step. If you've never gone through it to the point you think you're going to go out and just buy all of this from businesses 'taking cash', having people who've been there, done that, might save your skin.