Catherine;
A search on GunsAmerica once again shows that if you take your time, local snooping beats internet. The prices there range from high to outrageous. My personal opinion is that you'll have better luck poking around older out-of-the-way gunshops, rural auctions, pawnshops, and reading the classifieds every day.
Sub-$400.00 39's are out there, you just have to do the field work to obtain one. For me, that's an enjoyable project in & of itself. Again, personal opinion, I'd rather have an older 39 than a box new one anyway.
900F