"About how much would you estimate? Like $500? "
about that probably, call a masonry supply house and they'll tell you real quick exactly what you'll be looking at for your area. can probably be done by you within two days, providing that the base is poured a few days ahead of time. use type S mortar (premix), precast chimney block (if you can find it, use the block designed for round flue tile, round flue tiles are available w/ self-aligning ends, male/female- male end points down) just remember that you want 2" to combustibles which means any framing if you have the chimney go through the middle of the house somewhere (the best location). even though it's cement block you can tile/stucco w/ mortar etc. the block inside the house to allow it to be exposed and still be asthetically pleasing. pretty simple really, pick a location, cut holes in all three levels w/ reciprocating saw, rehang floor joists cut, pour foundation- wait a few days, start laying block and flue tile (don't forget fire clay between tiles), make sure it's plumb, when you get to roof level flash it, then continue up untill 3' above any roofline within 12' teminate w/precast crown available at masonry supply house, seal well around top flue tile, and you're done.