I'm no expert, but...
I looked into this after reading something on here and was surprised at the cost as I would have expected them to be more expensive. For stuff like this I use the following
CPC or
Farnell, yep they are the same company but offer different things. I'm not sure how the prices compare to eBay or elsewhere as once I looked at them I realized I don't know how to weld so gave up for the time being. Also they are many 'trade' but I think they will supply to the general public.
HTH.