"Dharma Dyes" are actually fiber reactive dyes its just they are sold by Dharma trading company. Only one company makes them(don't know the name) but many different companies buy them(i.e. Dharma, Jacquard, Prochemical), remix base colors to make a wider selection, and resell them.
Dharma is probably the easiest place as any to get them. Though if you have a local art supply store(not a craft store) they may carry them, too(probably the Jacquard brand) Ask for MX Fiber Reacive or MX Procion Dyes, they are all the same just different names. This may be the way to go if you just want to gve it a try without having to invest much(although Dharma is very reasonable) i.e buy one or two colors which isn't very cost effective shipping wise.