If inexpensive is a must you may check out the stables of some guiding
outfitters. They don't like to use stuff that looks badly used and you
can often get a year or so old vest for a fraction of its cost new. It
will also be porpose oriented. Kayak.
I use a Lotus and own a Kokotat PFD as well as some other stuff from
Mustang. The Lotus and kokotat are my favourites.