Cheapest laptop with T3 and eGPU support!
Currently TB3 notebooks are premium products. That may change in the future with Intel promising on-die TB3.
For now, look at the Acer Nitro Black series as an affordable TB3 candidate system. More so if limiting yourself to older 6th gen Sky Lake rather than the 7th gen Kaby Lake systems. You might get deals on Dell M3510 or HP ZBook 15 G3 systems as well. Pricing varies across regions.
If you don't mind looking used, as Nando suggests, Ex-Biz Dell M3510s are starting to appear on the market. BEWARE however not all 3510s are created equal and some do not have TB3 - be sure to check with the seller first. I nearly made this mistake.
XPS 13 9360 + Acer Graphics Dock
Cheapest might now always mean best. Cheaper laptops usually have drawbacks, such as poor thermal management. We're talking gaming here, so the CPU will be doing a lot, too! Having an i5 on a tablet-pc (think HP's Elite) with inadequate cooling will result in a 1.5Ghz two-core CPU quite fast (never mind HT). This is very poor for gaming. At the very least, look for PCs that do NOT throttle down (too much) under CPU benchmarks.
Well, it has been over a year since I started this discussion and still there seems to be no affordable T3 4-lane laptop available in the market. I thought that since Intel announced that the royalty-free program for T3 from 2018 we will see many new laptops supporting this standard...Why it takes so long to se sub-600$ basic laptops with T3 support?
How about looking at Clevo N141WU or older model N131WU ? There are multiple resellers across the world who sell this model under their brand. For example System76 Galago Pro. Price is below 1000$, quality is not the best, but this is the cheapest Thunderbolt laptop I know of.
@nikaru Even without royalties, it's an extra chip (+complexity) that is adding to the cost while being useful for only specific use-cases. Plus anything that might increase returns or support calls is not a friend of the budget producers As @nando4 says, until we get (non-premium) Intel chips that actually have TB3 on-die, this is unlikely to change.
2017 HP Spectre x360 15 i7-8550U GTX150 + GTX970@16Gbps-TB3 (HP Omen Accelerator) + Oculus Rift + Win10 [no guide]
HP Omen Accelerator Thunderbolt 3 enclosure legs stand removal walkthrough
Employed by HP, but my posts and opinions expressed on this forum are my own.