HDMI Leads?

Does anyone have any info on these, as I am getting confused, especially with vastly varying prices.
I currently have one which I purchased from Asda for £12 (3metre), and it seems fine. Good picture, good sound etc.
I popped into the local maplins and I noticed these "Monster" HDMI leads, gold plated, gas filled and all the X's, purchased it, plugged it in and the picture was slightly worse.

So I suppose my question is, "Are HDMI leads similar to scart whereby you can get fully wired types or not" ? It seems a strange question as the "Monster" lead is £48 dearer.

[Graham M]

No, completely different. HDMI is fully digital and doesn't have many connecting wires anyway. You should see no difference at all really between a £3 eBay Job, a £50 Monster cable and the Freebie one with the V+, it being digital, it will either work, or not, there is no in between apart from freezing, blanking and blockiness.