Holy Moly that is expensive! I know it sounds absolutely crazy but I never paid more than $80 a pack and they were super high quality. Try the website fullshine or on amazon, using GooGoo hair. I couldn't afford $600-$800 and honestly, I've never used synthetic they've always been high-quality human hair.
These are my go to! I hope this helps.
https://www.amazon.com/dp/B0785Y59QP/ref=twister_B0814SP9DY?_encoding=UTF8&th=1