[Rubick]

Hi all.
Apologies in advance but I am new to all this, and hope I am now on the correct forum (kindly redirected by another member), and excuse me if this is regarded as cross-posting.
To explain: I have spent hours now looking for what I thought would be a simple item...
I listen to all my music through my PC (stored on my hard drive) and I occasionally stream live soccer or listen to internet radio on the same PC. When I have to visit my kitchen, I would like to be able to hear the same broadcast/music. Simple?
I am not looking for hi-fidelity at all - I just need (I think) an audio sender (I have old PC speakers) to allow me to continue listening in the next room without jacking up the sound and ******* off my neighbours!
I don't need sophistication - simply an extension of the noise the PC is making, bleeps and dings included.

Many senders I have researched will 'send' the audio signal, but cut the sound from the computer (mostly USB-based). I need both sets of speakers to be audible at the same time (I think the transmitter/sender should be plugged into my microphone jack for this to work).
My apartment runs a Wi-Fi network and I have a cordless phone (if that affects anything), so I need to be able to switch channels to avoid interference, I believe.

Please can somebody recommend a product? I live in France, but have no problem with using UK adapters if necessary (not sure about the States and the voltage difference).
I didn't want to spend much more than £50.00, but considering the man-hours spent looking I should have forked out a grand in the first place!
All help gratefully received... Internet forums have never let me down yet!.
Thanks for taking the trouble...
Cheers.