I've had good experience buying chain by the foot at Rio Grande
They also sell other findings.
The price for Ruby varies a lot and depends on a variety of factors
that would require the stones to be seen by an expert in person. I
would take them to a reputable jeweller that has a Graduate
Gemologist on site and ask their opinion. They may charge you a
small fee, but may do it as a courtesy for you.
I hope this is helpful :)