So the Cube Mix Plus with M3-7Y30 and internal M.2 2242 slot has been mentioned before, but I think at current prices it deserves a hard look at.
The Cube Mix plus is being sold for $330 (
https://www.gearbest.com/tablet-pcs/pp_590393.html),
It can be paired with an Ipega 9023 for $20 so that they whole package would be $350
https://www.youtube.com/watch?v=tXhpbevD95MSpecs:
OS: Windows 10
CPU: Intel Kaby Lake Core M3-7Y30
SSD: 128GB - Has an internal M.2 2242 slot
RAM: 4GB
External Memory: TF card up to 128GB (not included)
WIFI: WiFi 802.11a/b/g/n wireless internet
Bluetooth: Yes
Screen type: Capacitive (10-Point),IPS - screen size: 10.6 inch , Screen resolution: 1920 x 1080 (FHD)
Camera type: Dual cameras (one front one back) , Back camera: 5.0MP with AF , Front camera: 2.0MP
TF card slot: Yes
Type-C: Yes
Micro USB 3.0 Slot: Yes
3.5mm Headphone Jack: Yes
DC Jack: Yes
Docking Interface for keyboard: yes
Battery Capacity(mAh): Built-in 7.4V / 4300mAh ~ equiv to 8600mAh 3.7v battery
Material of back cover: Plastic
G-sensor: Supported
Speaker: Built-in Dual Channel Speaker
MIC: Supported
WIDI: Supported
Additional Features: Bluetooth,Gravity Sensing System,MP3,MP4,OTG,Wi-Fi
Product size: 27.30 x 17.20 x 0.96 cm / 10.75 x 6.77 x 0.38 inches
Product weight: 0.7000 kg
Package weight: 1.9000 kg
It can be modded to improve heat dissipation by doing the following mod:
https://www.youtube.com/watch?v=AOd-ZI9YbMUP.S Why can't I embed youtube videos , has something changed on this site?