You can buy extra long cat6e patch cables, just run them under the edge of the carpet and under the doors, if you have hard flooring you could also clip (neatly) or run mini trunking on or above the skirting board.
However for the sake of 1 x 6mm hole through the wall that can be covered with a RJ45 outlet box and if then removed at a later date if required, the hole is very easily filled with polyfiller.
Whilst wireless can in some situations work very well, it also has its downsides interference can be a big problem and its not as secure as wired, and for serious gaming I would always go for a solid 10/100/1000 wired network.
Of course wired or wireless if your ISP sucks you might have gaming problems anyway!
so, get a job
save up and subscribe yourself to a gaming focused ISP with fat pipes
save some more and buy a gaming PC
then save for your own place/car
not nesseceraly in that order
SD.