Your local electronics store has just started selling time machines, anywhere doors, and invisibility helmets. You can only afford one. Which of these do you buy, and why?
The anywhere doors are moot. The time machine can take care of that. I’m assuming that the time machine goes anywhere and any time. So, just use time machine to go where you would have if you had the anywhere doors.
I supposed the invisibility helmet would be cool… but, I’ve read The Invisible Man, so I know how that turns out.
So yeah, time machine. Then I’d use it to go rob a bank in a different country in the future (one that doesn’t extradite bank robbers). Then I’d come back and change it to American currency and then buy the anywhere doors and invisibility helmet. I mean duh. On second thought I’d better rob the past. They might notice that it’s money that probably hasn’t been made yet, and think it’s counterfeit. At least with money from the past they’ve already seen that kind.