Maybe because there are tons of patents on HDMI cables?

    US6932640	Oct 22, 2004	Aug 23, 2005	Yun-Ching Sung	HDMI connector
    US7059914	Feb 20, 2004	Jun 13, 2006	Advanced Connectek, Inc.	HDMI plug connector
    US7192310	May 16, 2006	Mar 20, 2007	Cheng Uei Precision Industry Co., Ltd.	HDMI connector
    US20060148319	Mar 3, 2006	Jul 6, 2006	Advanced Connectek Inc.	HDMI type electrical connector assembly
    US8500489	Jul 15, 2010	Aug 6, 2013	Luxi Electronics Corp.	HDMI locking connectors

I seem to recall Display port is much cheaper in that regard.

Why doesn't everything have DP then?

Legit question, not sarcasm or anything.

probably because the early adapters of high-res in consumer markets (TVs, game consoles) were using HDMI in the first place (PS3 and XBOX 360). Displayport is more prevalent in PC use (not even laptops except macbooks which uses mini-dp).

I'm pretty sure most dell laptops have mini DP. My desktop grapics card also has two mini DP ports which I used with a DP to DVI cable without adapter. (something like https://www.amazon.com/SIIG-DisplayPort-Converter-Cable-CB-D...) You need an active adapter if you want dual link dvi though.

The most recent graphics cards (1080/1070) have 3 DP ports, one HDMI, and one DVI. Also, every laptop I own/use/know of has a mini-DP port too, across roughly 4 brands.

HDMI got their foot in the door first, but I think we'll be seeing more DP stuff in the very near future. The only downside of DP is the cables are usually more expensive.

Same with Lenovo where mini-DP is the standard for Ultrabooks.

Anecdotally, I see far more screens driven by HDMI, be they TVs or computer monitors of some sort. HDMI carries audio. Some DisplayPort versions carry audio. This may be a factor for mass market appeal.

But Orange Pi has HDMI and its all $10 http://www.aliexpress.com/item/Orange-Pi-One-ubuntu-linux-an...

I doubt most products on aliexpress pay royalties, or really give a damn at all about licensing.

What does the cable have to do with it? The HDMI adapter even says "does not come with cable". If you are talking about the connector, they are $0.43 each on digikey.

If the rest of the HDMI adapter board looks anything like the VGA adapter, with just passives and a connector, then they would be making a profit charging only $3 for it, let alone the $15 they are asking.

Based on the BOM at https://github.com/NextThingCo/DIP-HDMI-PCB/blob/master/v1.0..., you've got a Chrontel CH7035B HDMI interface chip, a serial EEPROM (probably used for EDID/HDCP key storage), and a LDO power supply for those chips. That definitely counts for the additional cost.

If you ignore the cable, you still have an annual fee + per-product royalty (though the royalty is like 15 cents for HDMI) to have HDMI + HDCP.

The annual fees are 5-10k for each (even in small volumes), and they may just be trying to make up the cost.

It's not a requirement at all, it has composite video build in that can be used if you need video. You can also just run it headless, I run most of my Pis headless.

Not everyone needs HDMI; I use my Raspberry with composite just fine.