I’ve tried the cheap thermal long underwear and I’ve tried the expensive thermal underwear, too. There is a place for both in your wardrobe. But cheap doesn’t have to mean low quality. Here is what I’ve experienced:
For inexpensive thermal long john bottoms:
1. Stick with Hanes. The weight is reasonable and they seem to hold up well.
2. Merona (Target Store brand): Hit or miss. The weight is good, but the fit and wear can be iffy.
3. Fruit of the Loom: Pass on these. They’re way too thin and they wear out too fast. They also have a tendency to tear along the seem.
For thermal underwear tops:
1. Although they’re a little pricier, go with the Carhart thermal tops. It’s worth the extra money and still reasonably priced. The only negative to the Carhart thermal tops is that the hole for your head is unnecessarily big.
2. Starter (Walmart brand) mock turtle neck. This is a polypro/spandex blend that is very similar to the Under Armour base layer. They’re cheap, but warm and they hold up pretty well. I’m on my second season with these and they’re still going strong. These sell for around $12, making them a bargain.
3. Merona (Target Store brand): The tops fit a lot better than their bottoms/pants.
All of these will be good for layering, down to about 20 degrees. Colder temps will require a thicker base layer.