purchasing a gas kiln

hi all,

my husband and i are planning a move to a new home in a couple of years, and
part of the plan includes a studio space for me, in which i plan to install
a small gas kiln.  my question is, how much can i expect to pay for a new
kiln, about 10-12 cubic feet.  how safe is it to purchase a used gas kiln
and what should i look for if the opportunity should present itself?

thanks in advance for any help you can give!