Using Late 2013 MacBook Pro with LG Ultrafine 4K Monitor - USB-C to Thunderbolt 2? I bought a used LG Ultrafine 4K Monitor with USB-C to Thunderbolt, the ones Apple are selling, for a good deal. I assumed I could make it work with a simple USB-C to HDMI cord, but this didn't work out.

Is there any adapter that can use my Thunderbolt 2 port with the USB-C on the monitor?

I've seen this one that looks like it's for use with old monitors and new laptops, but will it work if I plug it into the back of the monitor and then connect the Thunderbolt 2 to my computer? 

https://www.amazon.com/Thunderbolt-Adapter-Backward-Compatible-DisplayPort/dp/B019FPJDQ2/
No. You need a USB-C connection to work that display. 

You’ll spend hundreds of dollars to translate the video between formats since it basically is a small computer / device that takes power and re-encodes the signal.

Far cheaper and less hassle to resell your display (or trade / buy-sell used Macs) to get your gear on USB-C or not on USB-C.