OP here. Follow-up: I thought I should share this. I ordered and received the wire in the link below, which was suggested in this thread, and after careful inspection, ended up returning it. The ebay listing states that it is copper AND, there is a prominent close-up pic of the end of a wire stripped, and it appears to be copper.
When I received the roll of wire, I stripped some insulation off the end, and the wire was silver color. I thought maybe it is just tinned copper, so I scraped away a bit on the strands and I also clean cut the end, and inspected the wire under well-lighted magnification. There is some copper, and it might even be tinned copper, don't know, but if yes, the coating is not thin at all. Bottom line, per the listing and pic, I expected 100% copper or very close to it. But the percent of copper is clearly significantly lower than that.
The insulation is quite thick and I really liked the light color (it's a cream color) for an RV roof. But due to the copper content issue, I returned it for a refund and bought a different product that did turn out to be 100% copper. Thanks again to everyone who responded to this thread!
ML Solar, ebay
