No one makes better glock mags than glock. They also get much cheaper than $30 each if you wait for sales or hunt around.
$16 before shipping one month ago. Out of stock but these deals pop up fairly often: https://www.reddit.com/r/gundeals/comments/c6kbik/magazine_g17_gen_4_17rd_mags_1569ea_shipping_tax/.
I have three Magpul 17 round magazines. I have had no problems with them.