If one does not have any experience, one will not do the right thing.
Retailers are not doing most players a service either. The pollution of low end products by companies that want to make a quick buck has not helped the industry.
I used to work for an Airsoft supplier that got these lab goggles rejects. Poor ventilation, bad visibility and just looked stupid. But, he got them for 1.30 each and then flipped them to stores for 5.40 each...
"We made great margin!"
I fought with this guy for months...I was eventually ousted...he kept his job...but now this company went from a 40 million dollar a year company to just under 11...and they are still dropping...hmm...great idea...
But another thing about thermal lenses. You still need to keep hot moist air out of the interior goggle space.
The lenses themselves is not the be all to end all.
Auxiliary ventilation is still require and a sweat band that keeps excess moisture from dripping in will significantly help keep your googles from fogging up and that includes thermal lenses.
I rather use a "nightmare" that shoots like a dream over something that looks like a "dream" but shoots like a nightmare.
Don't fear the gun...fear the one that's wielding it!