Underlayment depends on the moisture from your floor.

I am not a big fan of the practice at all in long-term buy-and-hold properties.There's very little guarantee that the wrapping and caulking will be done well enough in the first place to really keep out moisture over the long-term.

We prefer the heavier product with the cushion/moisture barrier attached.

Says it was indeed moisture damage coming from outside, not costly to fix from what they say.

Given the slope of the lot and the fact that we are putting in some good foundation drainage, we don't think there will be any moisture issues with the crawl and don't plan to put in a sump pump.

Also, people with sufficient funds will leave these areas and the area will go into further decline.Climate - Properties in areas with hard freezes and excessive moisture will tend to require more maintenance than in milder and dryer climates.

@Tammy PriceOne more thing, if you decide to finish your basement make sure you have NO moisture issues that will lead to mold. 

Of course, with all the walls exposed, it would be better to also install a french drain to take moisture away from the walls.

The moisture underneath caused it to rot and be invested with carpenter ants.

Pricing average vinyl laminate planks, durable, and waterproof (which costs more) at around ~$2.70/sq. ft; soundproofing moisture barrier underlayment at ~$.50/sq. ft.; and a labor cost of $2/sq. ft.