Where can I get inexpensive jewelry repaired in San Francisco?

I have a relatively inexpensive ring that needs to be resized (I spent around $80 on the ring, which was handmade by a local artist – I think it is probably gold plated but not solid gold) and a pair of inexpensive earrings that need to be fixed. I looked for jewelry repair on Yelp but most of the places listed were for fixing very expensive jewelry – I called one place that said they won’t even do it if it isn’t gold or platinum. I don’t want to spend more on repair than what I spent on the ring – I was hoping to find someone who would do it for $20 or less. Anyone have experience getting a cheap ring resized or other easy repairs? I am hoping to find someplace that is either in the Mission or downtown near Powell or Montgomery BART. Thanks.