I won't talk about MY proposal for doing this without partial payment. but I am POSITIVE that this is not a CURL style implementation. I have had a lot of people talk to me about this feature over the years.
But the bottom line is that what you are doing is against the terms of craigslist. And I would insist I get it in writing that it's not my fault nor my liability.
I mean, you SHOULD call Craigslist and ask for the option to do this directly with an API. But they are changing nearly every channel to charge for things like that, so get in line.
IF I get chosen for this, I don't know what that Escrow requirement is. But I'd require $400 up front before I disclose any information about my design. If you don't like my design at the point, it's your loss.
It's NOT going to be curl, and it WILL require some software and hardware on your end, and it will also require a VPN subscription of some sort most likely, so i'll put that in the requirements. I'm pretty damn certain I can deliver this requirement as if it were a piece of cake at a wedding. The most graceful thing you've ever seen.
But it's NOT curl, and you won't like the design. but it's the best way to do it.
I am not gonna take a bunch of bitching about my design. I'm a crazy ass programmer, and I've done a LOT of browser automation tools over the years, There is a hard way to do this, and an easy way. You don't SOUND Like the type of person that is going to be told how to do this.