On Sat, 29 Dec 2012 14:42:57 +0000, MM wrote:

So what would I need to spend to buy something that would test the
wifi-connection to the "TP Link TL-WPA281 AV200 Powerline Extender
with Wireless N Access Point"?

Buy a cheapy Samsung wifi enabled Europa phone for 20quid. Doesn't
need to be unlocked if you're only using it as a wifi tester.
Alternatively, ask anyone passing with a smartphone to see if your
wifi is working.