It's a conspiracy to make you use your PI (and to drop Windows and move to Linux) :P

I see that Amazon has the TM04 for $30.

I use this:

https://smile.amazon.com/dp/B012ZNMUL6/

It plugs into any 120V outlet, has a built-in battery that lasts at least a full work day in case you can't find an outlet nearby, and as an added bonus can be used while you're on the road to make a personal wifi network so you can use a chromecast on the hotel tv. I got mine two years ago and the battery is still going strong.