Footnote - Sky want £199.00 for a new box. What a rip off!
Two points to note :
- There are multiple Sky STB models, Sky tend not to sell you the cheapest one
- There is nothing stopping you from sourcing a STB from an independent (which I would classify as a preferable route to Gumtree or eBay)
I had my fair share of problems with Sky recently, bought a new box from an independent for £100..... and it didn't cost me anything in the end because I got Sky to pay for it.