Hi. Does anyone here know of the best place to get daily updates on the price of sterling silver, 9ct and 18ct gold?

Basically; Customers usually email me for a price on a piece of bespoke jewellery - I try to slot the "price of the day" into my calculation. Problem is; I don;t want to phone & pester my caster for the silver / gold price every time someone makes an enquiry.

I had a whole bunch of bits cast up about a month ago and I was charged metal prices as follows:
£0.84 (g silver)
£16.31 (g 9ct yellow gold)
£33.37 (g 18ct yellow gold)

These figures don't seem to bear any resemblance to the figures on the Cookson site from a month ago.
The Cookson site gives the "gold" price , but does not break it down further than that??

If anyone can shed any light on my mystery, it would be very welcome! Thank you.