Under Armour or Carhartts?

I do construction so I am outside all day at work. I work on the water so I'm trying to be prepared for this winter. I am kinda tight on money and want to know what is better for cold weather. I have two options, go with the Carhartt overalls or use the under armour cold gear series (Leggings and shirt). If I went with under armour I could wear thermals and multiple layers over it buy I'm not sure if that would be warmer that Carhartts. I have tried neither but both cost about $100.