Edit:
Figure I'll drop my iPad monitor album in here since that display was mentioned earlier.
Not bad! But you've got to factor in the cost of the iPad chassis + digitizer, which I find normally will run you around $15-20 for the chassis, and $8-10 for the digitizer. Plus you have to be mindful of customs, since most of the chassis are considered "knock off" and customs just loves to confiscate them for trademark infringement (happened several times...)
Another option is to laser cut an enclosure:
Glue the pieces together with CA or epoxy and then use double sided tape to hold the LCD. I got a sheet of 7 enclosures cut at once and it cost me 70 EUR (so around 10 EUR each case). It's 25mm thick.
I have the original design files if anyone else is interested in cutting their own case!
If anyone lives in the EU and wants a case, send me a PM. I have 3 extra cases and would sell them at cost + shipping. Shipping outside the EU will not be economical due to the size/weight of the pieces.
I'm using the abusemark adapter, but you can also find HDMI adapters on AliExpress for the LCD. They run around $35 USD, however they're 12V powered not 5V, so USB power is not possible.
https://www.aliexpress.com/item/4K-...QX1-SPA1-SPAV-SPC1-2048x1536/32765195617.html
If you want higher resolution, a great panel is the Sharp
LQ156D1JX01. IGZO 4K in 15.6" and you can buy it for around $100 USD from AliExpress. If you want matte, then go for the Sharp
LQ156D1JW04, although the price is a bit higher around $130 USD. Controllers for this display are a problem though, no one has a cheap controller/adapter available yet. Don't go for the AUO/Samsung/LG 15.6" "4K" panels. They're pentile (RGBW), 48Hz refresh, and utter garbage. But they are cheap, so if the price seems too good, it's because the panel is trash.
I should soon be receiving samples of a UHD controller for the Sharp from a Chinese manufacturer. HDMI and DisplayPort input (supposedly with MST support, to be verified). Cost is around $130 each though, so it's less of play money and more serious investment ($130 LCD + $130 controller). I'll update once I've tested it and confirmed it works.
The iPad display can be done for quite cheap: $25 LCD + $35 abusemark/ali adapter + $12 laser cut case. However it won't offer as much protection to the LCD as putting it inside an iPad chassis + digitizer.