Massive difference in fence prices!

I am trying to replace an ugly chain link fence that is currently around my ingroiund pool. The quotes I have received are so wildly different and I dont understand why.

I am getting 150ft of Aluminum 4ft fence (basic design), 20ft of vinyl to hide my pool equipment. I was quoted $8000 from company A who uses "on guard fence systems" however the fence has screws and I dont know if I like that.

Company B quoted $12500 using active yard fence (screw less)

Company C quoted $13000 using catalyst fence (screw less)\

Is on guard screwed fence really so much cheaper than the others or lower quality that its worth paying a lot more for the others?