NDI on the cheap

Thinking of searching out a (used) box camera to match our PTZ cameras. (Basically, I'd like one to put behind a teleprompter because I can't bring myself to lose the PTZ functionality/advantage by putting it in the hood)

Currently, we have 2 Birddog P200 units, so naturally, I'm trying to find a Birddog PF120. Assuming this will match the most closely since they have the same sensor (on paper)?

1. Is this a dumb idea? (I know we're broke, but I don't want to be stupid too)

2. Is there a better idea I'm not thinking of?

3. Does anyone have experience with this unit? Is there a reason they moved on from it?

4. What's a fair cost for a used one? I'm seeing a large price range on eBay!

Additional information...

Yes, I need it to be NDI. I need to send it to more than one computer easily.

Yes, I'm thinking used. We're a high school media program. The nicer the equipment I buy, the faster the kids break it.

I appreciate any insight you might have to add.