[HELP] Wifi Card Solution

[Rashy]

So I started a topic about my Network Layout in here: http://linustechtips.com/main/topic/321021-network-layout-help/

But Wiring isnt really an option, although i accepted powerlines i am short on funding. With national exams on the horizon, and soon to be 3 months holiday with no money whatsoever = no income.

I've decided to get a Temporary Wireless Network Card, an PCI-E Adapter: TP-Link - TL-WN881ND

I can afford this until i get the Powerline Money, they are expensive here.

Problem is the router is about 30± meters away from my PC, i am currenly using phone tether, in the middle of the night when no one is using the internet at all i get max 500KBps although i have 6Mb UP / 3Mb DOWN and when i used to have wired i get 700KBps top now im getting 30KBps downloading a series episode... It furiates me and i get disconnected alot while playing csgo and bf3 so i cant play any online games. It's all because my cheap motherboard doesnt have one built in... Damn Budgets!

 

Questions:

1. Will the Network Card improve my speed? To the max. To the point where i reach 700KBps stable, to its full potential. To the last drop of internet Juice
2. The Model im looking at right now... How many distance it covers?
3. Is Powerline a reliable internet connection? Its really expensive, is it worth 70 USD with the speed of 300Mbps starter kit(a pair)?

Thanks, Suggestions appreciated.