It's an unfortunate consequence of the ridiculous markups on hardware add-ons, but if you're willing to apply a little elbow grease and look at resellers, it's not too hard to get what you're looking for for 1000$.

New:

  * 818$: cheapest T460 on the website
    * +270$ for i3-6100u => i7-6600u
    * +390$ for 500GB HDD => 512GB SSD upgrade
    * +470$ for 4GB RAM => 32GB RAM

Here's your 1000$ build:

  * 700$ for a T460 with an i5 on eBay (http://www.ebay.com/sch/i.html?LH_Sold=1&_udlo=700&_dmd=1&_ipg=200&LH_Complete=1&_sop=15&_nkw=t460%20i5)
  * 170$ for a 500GB 850 EVO (https://www.amazon.com/Samsung-2-5-Inch-Internal-MZ-75E500B-AM/dp/B00OBRE5UE)
  * 108$ to 170$ for Crucial's 16GB RAM kits (depending on specific specs)

If you're willing to part with another 200$-300$:

  * <800$ for a T460 with an i7 on eBay (http://www.ebay.com/sch/i.html?LH_Sold=1&_udlo=700&_dmd=1&_ipg=200&LH_Complete=1&_sop=15&_nkw=t460%20i7)
  * 340$ for Crucial's 32GB RAM kit (http://www.crucial.com/usa/en/thinkpad-t460/CT8304418)

If you're a more on-the-go person who needs a small laptop that needs to do it all, and do it all day then you might consider also checking out the x220T laptop.

They have a model with an i7, sometimes they have 3G sim readers, and has a touchscreen + touchpen (you can disable one, or both of these in software). These are great for taking notes, more then enough power to survive a day of real programming.

I've actually got an x220 with the original 6-cell and a slice battery, which puts me at 6 hours unplugged. It's not very impressive tbh, but it's been worth what I paid for it.

Lenovo's prices for a lot of upgrades (RAM, SSD) tend to be high. My recommendation there is to upgrade the things that aren't reasonable to do yourself/later (screen, WiFi adapter if you have choices between 2x2 and 3x3, backlit keyboard, fingerprint reader). RAM and HD upgrades on Thinkpads tend to be pretty easy (though I don't know about the X1 never having looked at one), so for those it may be better to get the cheapest option then upgrade on your own.

Yes, I actually did that with my SSD and memory. One of the things I miss of Thinkpads is the GPU. It seems like in the past two or three years it's been increasingly hard to find a Thinkpad T with GPU. I'm aware that the W have them, but those are beasts. I read somewhere that you could buy them through other countries, like Japan, but didn't look much into it.

They're not mentioned very often, but it looks like at this point for the T4xx you have to go with the "p" models to get a Nvidia GPU - the T460 and T460s are only Intel, as I understand it the T460p is somewhere between the T460 and the W product line - a little bigger, a little more expandable, etc.

Looks like you can also only get the GPU with the i7-6820HQ, so out of all the T product line there's a single CPU/GPU combination that's not using the Intel graphics. That may in part be related to the significant improvements in Intel's graphics capabilities in recent generations - starting around the HD4000 in the third-generation processors the GPUs are actually reasonably capable, and they've improved rapidly even from that point.

X1 has gone back and forth between upgradable and soldered on. Occasionally I will see an X1 at a price I'm willing to pay only to find out that I can't upgrade.