Deals fall through every day. I personally know of one deal that was close for three years. It didn't go though till last fall, but had been on the burner for that long.
I've said it before, I think SEO has always been open for a deal, or many deals or not, if he can't get his price. Would I take $.70 now or $10.00 in five years, I'm waiting for $10.00. Would I take $6.00 now or wait for $10.00 in five years, a completely different deal, one I might jump on. But if they are offering $5.50 & my minimum is $6, maybe we are close to a deal, but it dosen't mean we close.