Okay . . . well . . . take it from a seasoned provider . . . the ball was in your court, and you missed your chance to volley it in your favor.
after breaking the news that it needed to be launched in a couple of weeks for near-nothing,
This was your chance to put on the brakes and steer them straight. When you hear these flags, it's your turn to say "wait a minute - why do your poor decisions
become my problem?" Of course, you wouldn't use those words exactly, but this is the point you need to get across. This will make them sit up and listen. Since you passed this one, what's the message? FISH ON!
Everything else is a dangling carrot, it's clear who is selling to who here . . .
if I could mock up a site to help sell it to the client.
"So . . . this isn't even your site? Sorry, I work directly with clients. No exceptions" (i.e., I shake parasites off my coat tails, thank you very much . . . )
"they are interviewing several other firms"
They probably already have, and are feeding the same bull to all the others. Whoever comes back with the lowest price will be the one to get the job, and also the one they will be complaining about to the next developer when that developer realizes what they've gotten into.
There are entire books out there on how to screw web developers, how to get the rock bottom dollar by playing on our psychology, and this will continue to happen and get worse as (some!) wannabe "web marketers" become educated on the art of exploiting us.
I know that often developers feel the need to "serve the client" supersedes all other directives, but you need to stand your ground, set boundaries, never budge an inch. Define project scope ruthlessly or they will take up every ounce of slack in your proposal.
You know what happens if you do this? Two **major** things: They'll respect you. Second, this will set you apart from those "other firms." Most of them will be playing lapdog, eager to get the job, but when you stand your ground, it brings a sense of reason
to the table. The end result is that you'll build a **good** client out of them. But you need to take control of your own part in it.
I have had the most insane clients with the most unrealistic expectations come to me, and done everything short of turning them away. In the end, they appreciate it and turn out to be the best people I've ever worked with.
At this point, I'd weasel my way out of this one, don't even waste your time on the proposal. You just might get the job . . . and you are right, this will be a nightmare, and you might be the next one they dump. RUN Forest, RUN!