I just checked Dr. Crimmy's bottles, and they don't say what theirs are made of: LDPE, PP, HDPE, etc. But, I'll see what the best deal is on LDPE if that's what you want. I've got some bookmarked sites for best deals on plastic dropper bottles.
If you mainly want them for storage of the liquid instead of squirting it out of them & can use regular screw on, leakproof caps, instead of dropper tips & caps...I know what the best deal is.