I'm at the point of the relic quest where I need to get a weapon and two materia. The weapon was fairly cheap to find in the marketplace, but the materia are much more expensive (around 60k each). Do people usually just bite the bullet here and buy them?

More importantly, how do you meld them? Can I do it myself now that I've gotten Weaver to 19, or is there a chance for failure? I'd hate to spend 100k+ on these things and then lose them.

How exactly does melding work in this case?

Thanks.