They are ripping you off on both the patch panel and network cabinet. A patch panel shouldn’t cost you more than $50 unless you have very specific requirements and would do fine for years and years. The one they’ve quoted you isn’t actually expensive, just has a massive markup for them. Same for the comms cabinet - bit more expensive but a 6u one should be less than $250 and in reality you could just use a normal furniture if all you’re putting in is a patch panel and a switch.
If this was me, I’d review every quote and invoice from this builder and likely end up firing them if not considering legal action because it’s highly unlikely that they haven’t done the same to you for other quotes that you just didn’t catch.
Edited to add: a 24U server cabinet from the same maker is $653 and you were quoted almost that for a network cabinet that over 3 times smaller.
Something like below is what you’re looking for and is only $189:
https://www.selby.com.au/brands/raxx/6u-wall-cabinet-530-450.html
That’s an asinine statement to make and suggests a lack of common sense.
Any website can be compromised, even if only for a short time and zero click zero-day vulnerabilites exist. Companies are not the only ones at risk from this or the only ones with something to lose if their system gets compromised.
Common sense is important but not enough (and evidently not common enough).