Ill have -30 res in total which doesnt seem like its too much
It's usually not easy to amass -%resist. The facets doesn't drop often, and the modifier is rare on unique gear. Buying a want with lower resist charges is a solution, at least against bosses or boss monster packs.
So trying to figure out ways to play without it, at least until one starts playing more regularly in hell mode and find them on an occasional basis, is perhaps the most practical method.
And then, there is not usually too many options to use them in sockets. There is usually only one in the helmet and one in the armor. Although one can make compromises, use weaker armor pieces with more sockets, which can boost damage, but lower defensive capabilities, which can be quite risky in hardcore mode.
But, finding one, and using it in the correct gear piece, is very satisfying. Last ladder (hc) i found a near perfect griffon's eye. Then, i found a perfect lightning facet. That was a huge high point for me on a personal basis. That is kind of a find of a lifetime, especially for someone like me that plays honest and don't cheat, use bots, or buy gear almost at all. Very very low drop chance. Yet, lol, i had to level my sorc character a lot, since it does not work on traps... though using lightning with that was cool, did big damage in chaos runs.