I'll tell you what; if you can't afford to buy a few polyps, then don't bother. Armageddons are already fraught with problems and you're facing a challenge to keep them alive long-term. Getting a single polyp frag is only going to increase the chances that this frag will melt and you'll have wasted your money. $100/polyp is definitely top range, mainly because they are such notorious melters. Usually $50/polyp is about the cheapest you'll see them for sale at. If they didn't melt at the drop of a hat, given their rarity in the hobby they would probably command a higher price. Catch 22 though, cause if they didn't melt they wouldn't be so rare. I've tried them twice now and both frags have eventually melted. The first melted within a week or so, and the second was growing and thriving for almost six months and then suddenly closed up and melted. I guess that also doesn't count the time I got a frag several years ago when I first got into zoas/palys and had that one for a few months. Never grew and then shrunk up and disappeared. Also, every person I've known to have them, including the people I got mine from, have lost theirs eventually as well. I'll try them again though if I can find them, 'cause I love 'em.
I've actually made the determination that if I can get my hands on a few polyps to start over, I will be dedicating an entire tank, like a BC29 or something, just to them. It will have no other corals in it. My goal will be to get frags/colonies into every tank I have, and then let them take over the one tank and have an Armageddon garden!