Fob Proximity stopped working. Also Missing Fob's RFID Chip. (It's impossible to start right now)

I'm only able to post in the newbie forum, so I hope this subject is okay to post here.

The fob proximity functionality for my 2007 Prius suddenly stopped working. I'm assuming this is the issue because the proximity "Push To Start" and "handle sensor unlock" stopped working at once.

I tried to use the manual-start by sliding my fob into the slot to the right of my wheel, but that doesn't work. It turns out that's because I'm missing the RFID chip within the fob. (It's also my only fob)

My current goal is to just get the manual-start working so that I can actually start my car and start troubleshooting the proximity issues.

So I have two questions:

1. I did some digging and found someone who suggested the following:
   
   If it were me, I'd buy the cheapest used key fob (black or silver logo, it won't matter for this) I could find and then harvest the RFID chip from it. If the case was in better condition I'd swap that also. Reuse the back cover (with the logo on it) from your current key fob.
   
   You would then need to program the chip by using the first 5 steps of "Procedure A" in the "Chicken Dance".
   
   - RFID lost | PriusChat
   
   Is this actually possible? (If so, it could save me about $150)
   
   
2. Should I be starting with trying to fix the key fob like I currently am, or should I start somewhere else?

If you have any suggestions, please let me know.

Thank you for reading!