I am thinking of getting an automatic vacuum. First off, I own a 30 X 18 inground, kidney shaped, with a deep end of about 8 1/2 feet. I want to get an automatic vacuum. I have a few friends that have above ground pools and they all unanimously recommend the Barracuda. A Baracudda for an above ground is about $170ish, while the inground is almost double that. Why is there such a big differance? Will an above ground work in an inground pool??