I'm a tad stressed because I'm not as young as I once was, and my wallet isn't too thick.

Another effective option is a removable acoustic door plug—essentially a thick, custom-cut foam or dense fiberglass "cork" that compresses into the door frame to seal off sound when not in use.

Based on my research I'm hearing you need something5-mm or greater for the thickness of the plank12 mils or greater for the thickness of the wear layerany thoughts or recommendations?

Contractor Quoted $6,950 per entrance with rebar and 6 inch thickness. 

Its easy to install (reducing labor costs) and really affordable depending on the wear layer thickness and brand.

(I don't recommend insulating the ceiling of the crawlspace--it will cause condensation and dripping.)Make sure there is some sort of vapor barrier on the floor of the crawl space--either thick plastic sheeting or cement. 

You’re gonna have to get thick skin too if you’re gonna last, which I really hope you do.

Also as Eshe said, do a thick mulch-thicker than you think as it is what will help keep weeds down. 

Happy to connect - we are real estate investors and run a property management company in RI so we're in the thick of it :) and can be a good source of info to start in this area.All the best,Laurence

Consider adding thick curtains, rugs, door draft blockers, or even investing in a white noise machine.