ZD From what I can see the garbage is in large dump trucks which is dumped for them and the volunteers then search it. The volunteer are are wearing protective garb so there is no danger to them unless they don’t follow protocol.
$2,000.00 is kind of high for Tefillin unless it’s 2 pair Rashi & Rabanu Tam. As far as where do you draw the line a picture in the newspaper of a page in a siddur or chumash in my opinion is not shamus at it was never printed with the intention to use it as a siddur or chumas. A part of a siddur or chumash that was printed to be used as a siddur or chumash or any other holy book would be considered shamus.
I think that greater precautions can be taken to safeguard Tallis and Tiffilin not only at this shul but in all shuls to insure that it doesn’t happen again. For example, not having a garbage can in the same room that tallis and tiffilin are stored. Placing them in a cubbyhole that doesn’t have a door than can be locked even just by a magnet to insure the contents don’t accidentally fall out.