It depends where you are. Microcenters generally have them for $5 ($10 for the 'W'), although for Pi Day they're both on sale for $3.14. Sadly, there aren't any near me, but I had a relative who is near them pick up a literal handful last time they came down.
Several online places have them for $5, but shipping 'kills the deal' as they say.
Re:New Raspberry Pi Model B+
by antongribok on Wednesday March 14, 2018 @04:30PM
(#16588030)
MicroCenter is where I buy them. I happen to have one close by.
They also sell the normal RPi3 for $29.99 instead of $35.
Re:New Raspberry Pi Model B+
by morganvachon on Thursday March 15, 2018 @06:42PM
(#16597099)
I got my last two Pi Zero units from Vilros[1], they have the Zero W for $10 which is the intended price from the RPi Foundation. To me, it's worth the extra $5 for WiFi/BT with no dongles.
[1] https://www.vilros.com/shop/raspberry-pi/raspberry-pi-zero-w...
I have yet to find it - you can get them cheap, but no where near what the RPi Foundation advertised them at when they first were announced/launched.