Once the ground thaws I am having a 6 foot tall black vinyl chain link fence installed. I have contacted 3 companies so far, one has already given me a quote. The quote I have is 4200 dollars installed and includes taxes and fees. They noted that every single post is set in concrete. One of the companies uses post anchors by default, and concrete if requested. The third, Central Iowa Fencing, pounds in the posts 3 feet into the ground, and I believe use concrete for terminal posts. Is it normal to not use concrete for chain link posts? They have really great reviews, and I'm assuming this quote will come in cheaper. They offer a 5 year no heave warranty on the work, which concerns me a little...I believe my soil has a lot of clay, because in my front yeard, you can see a ton of cracks in the soil when it's really dry. I'm assuming I will be in this house for at least the next 10 years. What are your experiences?