I think it depends on the company as well. When I see an add that says, 1500TT minimum, 3000TT w/ type preferred, I get the feeling that they can't go lower than 1500. And as others have mentioned, sometimes it is an insurance thing, and some ads will say this. But on the other hand there are companies that will take lower time requirements. My current job asked for 1500TT and 500 multi. I was about 100 short on the multi, but I had more total time, lots of IFR etc... so they looked past the multi.
When I started ground school I found out that some of the guys had 800TT, but one had previous 121 etc... so it never hurts to try. Just depends on the company, so it always helps to get some insider information about how "hard" the minimums are.