Why are Chinese Silkie hens hard to find?

We get asked this question all the time.  There are Silkie breed-specific factors at work here.

1) Chinese Silkies are very slow to mature, taking 6 - 8 months to reach sexual maturity. In comparison, a meat/production chicken is ready to slaughter at 6 weeks of age.  A 6-week old silkie chick that is just getting old enough to come off of heat, is around the same size as a 2 week old meat chicken.
2) Silkies are lazy egg layers.  Hens will only lay about 2-3 eggs per week. Also, when broody (as silkies constantly are!), they will stop egg production for weeks to months at a time.  They just don't have the egg output of most other chicken breeds.
3) It is often difficult to determine a silkie chick's sex until they reach maturity at around 6 months old.  Not only are they slow to mature, but the variances between the sexes (comb size, wattle size, crest feathers) look identical at a young age.  So a rooster looks much like a hen until adulthood.  Hence breeders can't really cull out silkie roosters from growing pens to allow extra space for just the females.
4) The only reliable, proven way to sex a silkie chick is via DNA testing from blood or feather samples. In Australia,  the cost of each test is between $15 to $18 for each bird tested. This increases the cost of a DNA sexed silkie pullet by $30 to $40 each, taking into account the time and hassle factor for the breeders, plus the fact that we've had to pay to DNA sex roosters nobody wants. So we don't tend to DNA test much.
5) Small pen spaces make raising a large flock of baby silkies difficult for backyard breeders. Because boys look just like girls, breeders are forced to feed, medicate, vaccinate and care for a mixed-sex flock of birds in restricted space until sexual maturity at 6 months.  That cost has to be recuperated somehow.  The sale value of a 6 month old silkie rooster is much less than the cost of raising it to that age.

Can you guess my gender yet?  Nope!
(Our 7 week old bearded Silkie chick eventually turned out female)

The cheapest way to get into silkies is to buy fertile eggs and incubate them yourself.  Small incubators are readily available on Ebay.  Second to that option in cost, is to buy week old silkie chicks.  Cull the roosters at 6 months, keep your pullets and in a year's time you will have valuable hens.  That’s what we breeders have to do. 
It’s slow, it’s costly, it’s a lesson in patience, but they are so worth it!