Hardware wise that is about right on the price. Without RAM or hard drive(or hdd caddy) those usually run between $50-90 on ebay. Once you get to adding the HDD and Ram it comes out to around there. Can't really say much on the Windows install, I only really run linux on the thinkpads I buy.
I was looking at the W520, what is the gaming performance on that? Also how much did it cost used? Since my cash is limited I am planning to supend the purchase of a new laptop, for now it's my shitty x201, to go down to florida to see my grandparents over spring break, but what I want is power, I want to expand my skills into doing C++ development and gaming and video editing, and that is a primary reason that I want more power, and the reason I was asking around for a T420 because with a quadro, I might get 2 out of those 3 done with efficiency
edit: also what exactly are you doing with your w520?
As mentioned, gaming performance on mine is virtually non existent outside of running 15 year old games. Note that there are several variations of the w520: from i5 to i7, of which only the higher end version of the i7 supports ddr31600, while the rest are limited to 1333. GPU wise, you have 2 options, the Quadro k1000m and k2000m. For the screen, you have the option of a 1080p TN panel with decent color calibration, and a 900p TN without.
My laptop is essentially the highest and model with the high end i7, upgraded 16gb ddr3 1600 RAM, k2000m GPU, calibrated 1080p TN panel, a 256GB msata SSD, and a 1TB SSD. Note that only the main hard drive bay supports sata 3, while the msata and expansion bay are sata 2 speeds. About the only modern games i can play are ones with the requirements of Diablo 3 and StarCraft 2, and to do so, i have to turn down the graphics to the lowest settings. Luckily for me, my gaming these days don't concist of more than this, as much of my games are much older.
What i actually use it for is for school, typing out documents, a computer science class learning C, old school gaming, and media consumption. Perhaps way overkill for what i use it for, but the KEYBOARD alone is worth it for me.
Now, keep in mind the t420 DOES NOT have a Quadro GPU, nor a quad core CPU. It's a dual core laptop with integrated graphics. Now while you can upgrade the CPU, you are still limited to the slower RAM speeds, and lower cooling capacity of the smaller t420, so throttling might be a thing. Also the color reproduction on the t420 is terrible, so for things like video editing or things where color reproduction is important , it just simply is not a good choice. For programming though, it's just fine.
Now the w520 has the cooling capacity for both the Quadro GPU and quad core CPU, a color calibrated display on the 1080p model (though it is TN), and the capacity for up to 32gb of faster RAM. With that said, it is more expensive at $500-700. I also popped in 16gb of RAM, and 2 SSD. All in all, I'm in this laptop about $1200. Again though, do not buy this laptop if you plan on any sort real gaming. For workstation stuff though, it's fantastic.
okay, so that is what you use it for, of which lines up with what I want to do, with the w520, just a small question, what operating system are you on? I plan to use linux, but if your using windows, just out curiosity, what kind of drivers are you using? I mean that you are in a forum here you might have tried some optimizations, does that work out? Also if your running linux, how is optimus, heard it's hell. Also when I said gaming, I meant doing more stuff like CS:GO and TF2 and a lot emulators
Out of curiosity, I turn off my GPU and ran CS:GO off the Intel HD 3000 integrated graphics. Honestly, its still perfectly playable at 30+ FPS. Rarely does it dip down below that, and tends to hover at 35-45. This is with max settings at 1080p. Diablo III, while perfectly playable on low settings at 40+fps on the K2000m, is nearly unplayable on the Intel HD3000 at 15-25FPS @ 1080p. Funny enough though, most of the time I tend to leave the laptop in the integrated graphics mode....
At the moment, I am on Windows. I was running Linux, but due to a hard-drive shuffle, and simply lack of time, I haven't got around to installing Linux back on it. I was using Arch at the time I was though, and really excited to get back on Linux.
The reason I leave it in integrated graphics most the time is simply out of habit from using Linux. Like I said, rarely do i play a game newer than Diablo 2, so integrated graphics tend to be plenty for my needs, and were really easy to setup! I tried using Optimus, and only ended up crashing the OS with it. It was also right around this time when I was starting to go back to school, so time was short in hand, and I simply went back to integrated and get that running smoothly first. Then, if I wanted to use something that would require a GPU, I would just boot into Windows. When I go and install Linux back on this laptop again, I think this will be the route I end up taking simply due to a shortage on time to really work out the bugs.