If there's something I have to say about vintage Star Wars, it's that you can't give it an accurate value anymore, especially if it's loose. As the carded stuff is really what maintains a steady value.
But I'd say it's worth 700-900$ according to the books (the 2001 books that I have LOL!). If you piece this lot apart, you might be able to get back around that. If you sell it as a lot, there's a big chance, you might score way less, perhaps between 300-500$ depending on the weather....Ebay weather!
Your Droid Factory is perhaps the most interesting piece of the lot considering its great looking condition and its degree of completeness. And your Death Star playset has all the hardest to find pieces, and worth completing. Finding the rest shouldn't be a problem. Get informed on what these two alone are actually worth, my best possible recommendation before accepting someone's offer.