I found something like this online that sold a pack of 36 crystals for $10, but that doesn't include shipping. When I found this at Walmart for about $3, I had to get it.
What are they exactly? I'm glad you asked. They're crystals that you flat iron into your hair. I put two of them in last Sunday night, and they lasted all week. But, I also did them in the left side and I normally sleep on my right side, so that probably helped keep them in. The first one came out Saturday and the last one did this morning.
There are a few downsides, though. You cannot brush your hair where the crystals are. That is kinda common sense. They also kept hiding under my hair at the top. I think the next time I do it, I'll put more in.
Putting them in is pretty easy. All I did was cut out the ones I wanted, peeled off the white sheet, and stuck the sticky part where I wanted them. It was hard for me to place them, though. But I also didn't have a good mirror. Anyway, after that, I took a flat iron and pressed them for about 5 seconds and peeled off the clear sticky sheet.
Between the online ones and these, I think I'm in the neutral zone. These are easier to get and cheaper, but you get less and only one color. Online there are more in a pack and more colors to choose from, but it probably gets expensive after shipping and you also have to wait.