bro.... laptop can last or cannot last mainly depends on how u treat it... if u put it in non air con n no ventilated environment... PC oso will burn if u on 24/7 la.. i hv optiplex 9020 MT burn becoz client use it at mainframe for cctv but non ventilated.. tat business spec oso met it maker...

asus k501 no problem if u put good care like clean the fans every 3-6 months.. repaste thermal gel every 1 yr...

However wif tat price of 3199... even though i7 but u series

Take Inspiron 7559 i5 quad core gtx 960m at 3399...

Most common i7 in the market comes with either a quad core or dual core. U series = dual core. Dual core is more power saving compare to the quad core ones.

For e.g,
U series = i7-6500U, i7-6600U
HQ series = i7-6700HQ

There are even more efficient processor than the i7-6700HQ such as i7-6820HK. 

this r the choices, acer nitro V, illegear z5, inspiron 7559.. this r the better options...

But at least he take initiative to ask.
Last time when i was a noob, i thought get an i7 = best bang of buck liao.   
Performance wise, i7 > i5 > core M > i3
Core wise, HQ > U

But U series processor means that it is towards power saving and lower battery life.
If you have the budget, the current best bang of buck would be the Dell Inspiron 7559. I would say decent in almost every aspect.
Asus K401U-BFR011T 14" Laptop/ Notebook (i5-6200U, 4GB, 1TB, NV GT940M, W10H) 2.5k/-
Asus A456U-FWX023T A-Series 14" Laptop/ Notebook (i5-6200U, 4GB, 1TB, NV GT930M, W10H) 2.2k/-

Since your budget is 2.5k, you can get Asus A456U, and upgrade ram/invest on a cooler pad for a long run. Whether your laptop is gonna last long or not, it is solely depending on the owner. Ventilation, maintenance and etc are very important. pandera999 gor gor has a 7 years Acer laptop that can still plays dota.

IIRC, you did mention to hunt for K501 before. But not sure which K501 model you mentioned though, but anyway, K501U comes with a better graphic performance than the one i recommended. But personally, i really do think that 8gb ram is a minimum requirement for windows 10.

Hope this helps a bit.

DELL INSPIRON 14(5459) LAPTOP
6th Gen Intel Core i5-6200U Processor(3MB Cache,up to 2.80 GHz);Genuine Windows 8.1 Home 64bit;500GB 5400 rpm Hard Drive;4GB Single Channel DDR3L 1600MHz(4GBx1);Tray load DVD Drive(Reads and Writes to DVD/CD);Stereo speakers professionally tuned with MaxxAudio by Waves;AMD Radeon R5 M335 2GB DDR3;Built-in 10/100 Base-T Ethernet LAN;3 in 1 Card Reader(SD,SDHC,SDXC);802.11ac+Bluetooth 4.0,Dual Band 2.4&5 GHz,1x1;1 Year Warranty

Rm2450..