Update waveshare-cm4-io-base.md (#571)

* Add third variant of the board
* Update prices to 2023 one's
* Update description of the board to match third variant

_boards_cm/waveshare-cm4-io-base.md

@@ -8,8 +8,9 @@ github_issue: "https://github.com/geerlingguy/raspberry-pi-pcie-devices/issues/1
 link: https://www.waveshare.com/cm4-io-base-b.htm
 videos: []
 ---
-This board has a 1 Gbps Ethernet port and features 2x MIPI-Camera connectors. It also has an M.2 M-key slot capable of using NVMe SSDs or other PCIe peripherals. It has a full size HDMI port, an RTC with battery backup (Version B only), and a 4-pin fan connector with a fan controller (Version B only). It also has 2x USB 2.0 ports and a built-in USB 2.0 hub.
+This board has a 1 Gbps Ethernet port and features 2x MIPI-Camera connectors. It also has an M.2 M-key slot capable of using NVMe SSDs or other PCIe peripherals. It has a full size HDMI port, an RTC with battery backup (Version B and C), and a 4-pin fan connector with a fan controller (Version B and C). It also has 2x USB 2.0 ports and a built-in USB 2.0 hub.
 
-Sold in 2 versions:
-* [Version A](https://www.waveshare.com/cm4-io-base-a.htm) ($20) lacks RTC, RTC battery holder, fan controller
-* [Version B](https://www.waveshare.com/cm4-io-base-b.htm) ($37) includes RTC, RTC battery holder, fan controller
+Sold in 3 versions:
+* [Version A](https://www.waveshare.com/cm4-io-base-a.htm) ($19.99) lacks RTC, RTC battery holder, fan controller
+* [Version B](https://www.waveshare.com/cm4-io-base-b.htm) ($27.99) includes RTC, RTC battery holder, fan controller
+* [Version C](https://www.waveshare.com/cm4-io-base-c.htm) ($21.99) includes RTC, RTC battery holder, USB-C connector on front, LED indicators on front, 40PIN LCD display port instead of MIPI DSI display port, lacks HDMI and USB FCC connectors, fan controller