This is what most manufacturers make to supply the demand for speed. Low tip weights are a compromise to gain fps. However, accuracy, penetration and forgiveness are not ideal with such as low weight broadhead. Arrow spine is chosen after you choose a broadhead (tip weight). It needs to be stiff enough to match your tip weight at your draw length and draw weight. I chose a tip weight of 270 grains. There is no good reason to restrict yourself to 100 grains.

After you determine the tip weight and arrow spine, you can choose the quality level you can afford on the arrows. If you have the ability or willingness to learn how to spine tune with a spine tester, quality is not nearly as important. If not, then buy the best you can afford. After that, you can bareshaft tune to find the perfect length to have your arrows cut to. Do all this and you'll maximize the effectiveness of your choices.