Unresolvable Problem (Wireless Gaming)

So I recently switched to wireless and it totally sucks for gaming. I did this because it was just too noisy downstairs for me to focus on my studies (where my modem and router are located). Now I get these stupid random spikes when gaming, and it usually gets me killed every time haha. My router is a WRT160N, and I'm using a Belkin USB Wireless N Adapter. I picked the one with the cord, so I could move it around for the best signal possible. I'm on Cox's 15/2 plan, and my speeds are just fine. I did some research on it already, and people say it's due to WLAN Autoconfig service searcing for networks every 60 seconds, but I have ruled that out because my spikes are completely random and not at 60 second intervals. Also, they happen ONLY when gaming. If I were to ping 192.168.1.1 -t or something just browsing the web, I would see no spikes at all. I would run a cable, but it's just too hard to this cause because I'd have to run it upstairs and then all the way across to the opposite side of the house. I hired an electrician to come have a look, and he said he'd have to charge about $400 dollars. No way my parents or myself would pay for that because that is completely unreasonable. Is there anything I can do to get this wireless gaming to work? I was thinking of buying a wireless repeater. Any opinions on this? Thanks in advance. I've asked for help from so many people! Nobody has a solution!