@PeterTselios Depending on how many ports are needed, "Switch B" could be a SG2008 (T1500G-8T is an older version), this is a 8 port gigabit switch that has one port for POE power in, and no POE pass through, it uses 802.3 af/at standard for power.

For APs with POE pass through, look for the Omada APs with "Wall" in the name and have 4 ethernet ports.  For POE pass through the AP must be supplied via a switch with 802.3at POE.  To power something like a Amazon FireStick or tablet you will need a POE splitter such as the TL-POE10R. 

  @JoeSea 

I don't need an 8-port, smart-or-managed Switch, a simple dumb 4/5 ports Switch with PD. It looks like there is no cheaper alternative from TP-Link though.

  @PeterTselios Correct, the 8 port managed is the only PD switch that TPLink has right now.  Unifi's Switch Flex Mini is a 5 port PD switch for 30 USD, it is "managed" but I think only through Unifi and I've read that it will just be a dumb switch out of the box.  I think I've seen a Netgear 5 port PD switch, but don't recall how long ago and what model.

  @JoeSea Yes, Netgear and ubiquiti are my only alternatives, unfortunately.