I like the common sense approach that SReilly mentioned,,, Do it and put the rest of the money in tools, wood, HVAC, etc.Hello Messy and welcome to the forum. My suggestion, if this hasn't already been done, is to have the loudest piece of equipment you use in the shop as is and do a perimeter check on what noise travels outside the shop now. It sounds as if you're already overthinking the problem. But I understand the thought process. What is the acceptable noise level? The lay of the land is also going to impact the distance the noise can travel. I have a neighbor behind my property (Preacher) who can hear my conversations while I'm on my deck which is mainly due to the fact that the two lots, all 10 acre lots, have a valley between them which seems to amplify the noise. My house has normal insulation with the shop in the unfinished basement which again, normal insulation except where the 5hp dust collection unit is housed. There I built a closet and lined it with rockwool sound insulation which deadens the volume considerably.
Aside from the noise, are you planning on heating/cooling this area?