Prices for ferrets vary widely from place to place, and depending on
where you get the ferret [4.4].  Prices for stores and breeders are
usually in the US $75-$250 range, typically around $100.  Plan on
another $100-$250 for a cage [5.4] and supplies [5.3], plus around $75
for the first batch of vaccinations [9.2].

Of course, there are also regular costs of caring for the ferret.
They don't eat much, so food and litter aren't a huge expense, but
there are also treats [6.3] and hairball remedies, plus the annual
checkups [9.4] and vaccinations [9.2].  In addition, though it might
not happen, you should be prepared to pay for at least one $300 vet
visit in each ferret's 6- to 10-year lifetime, from his getting sick,
being in an accident, or eating something he shouldn't [11.1].