Hmm, as far as I can tell all these add-in cards need a TB header on your motherboard as well as PCI-E 4x. If so they're not compatible with generic motherboards, but I haven't seen anyone try them without the header. Of course my old system doesn't have it but it's also too good to throw out, dual sandybridge xeons!
https://www.scan.co.uk/products/gigabyte-gc-alpine-ridge-10-card-thunderbolt-3-certified-add-in-card little pricey but not bad. Honestly with the cost of a dock making a new build entirely wouldn't be that much. something not ancient but still very capable... i7-3930k's (6core 12thread) are regularly under 100 on ebay, x79 boards can be difficult to find but not very. still DDR3 so you wont have to spent a grand on 16gb of ram (and probably have some ddr3 lying around already) and have a card running at full 16x without a bottleneck. if you're interested in looking into an overhaul, message me what you have and i can show you an idea of how much you could improve it on the cheap than just using this for a temporary boost (if your cpu/ram/hdd don't bottleneck it even more than the 4x limitation)
Overview section: "Compatible with Windows®-based PCs with Thunderbolt™ 3 port."
Gotta love how the discount is for students who are supposed to be studying and not playing games. Haha. Hot deal tho!
There's a review here: