i`ve been reading/looking at the posts on this site for over 2yrs. i`m not a pro installer but have layed over 25 hardwood floors, mainly solid by a certain danish manufacturer. if i`m unsure of anything, phone their tec department and listen to advice given. different area, different clip system. high moisture in slab, i`ll use the barrier they tell me to. never had a problem with any floor i`ve ever laid because i take the time to ask.

if you buy freshly cut flowers and put them in a vase with water, they will survive. hardwood is no different, it will continue to expand and contract due to moisture: live in Scotland, mostly rains and is cold, the wood will expand. summer we will get small gaps showing due to heat.

ps: 8$ a square foot, you cant buy laminate for that price over here.