Here's one I was encouraged to submit to recently by the respected head of a large writing group (I don't know her personally) - anyone can submit:
http://www.pentopressretreat.com/index.cfmYou have to be invited after they read your writing samples; then it is terribly expensive (by my standards perhaps it's just normal to spend about $800 before paying for the hotel). But the conference is small and somewhere on the video & website it said that 20% of the last conference participants were signed to a publishing contract - now THAT's impressive.
Anyone familiar with this one? It almost sounds too good to be true. I plan to submit, though I'm not sure if I'll go if accepted because I just can't see how I can afford it.
Lucie