I would like some advice on how I can boost/spread my Wifi for as cheap as possible.
I drew this magnificent diagram below to help demonstrate my predicament!

p.s not to scale
Red box is at the bottom of the paint masterpiece is where my Virgin SuperHub currently is. Ideally, I don't want to move it as that's where all our PC's etc are.
The WiFi signal starts to bite the dust towards the end of the kitchen extension (red line), so doesn't actually reach to the man cave at the bottom of the garden, which is where I need some Internetz!
The garden isn't huge, probably around 20ft or so.
So whats the best/cheapest way to get a decent signal in my man cave?
Good enough signal to stream videos, if that makes any difference.
I drew this magnificent diagram below to help demonstrate my predicament!

p.s not to scale
Red box is at the bottom of the paint masterpiece is where my Virgin SuperHub currently is. Ideally, I don't want to move it as that's where all our PC's etc are.
The WiFi signal starts to bite the dust towards the end of the kitchen extension (red line), so doesn't actually reach to the man cave at the bottom of the garden, which is where I need some Internetz!
The garden isn't huge, probably around 20ft or so.
So whats the best/cheapest way to get a decent signal in my man cave?
Good enough signal to stream videos, if that makes any difference.