I would be wary of that listing.
The import of FBT from the wild is banned across all the US. Therefore, all specimens sold within the US should be captive bred. Smuggling still happens though, even in “broad daylight”, so to speak. Given that this website does not clearly state that their frogs are captive-bred (as well as who they’re bred by), I would be wary of illegal smuggling. Even if they are captive-bred, a price like that tells me they’re just wholesalers who have little to no concern about breeding quality or animal health.
Josh’s Frogs is a great alternative, if you’re going with a large online retailer. They’re fairly transparent about their animal sources (every animal they sell is captive-bred), and they almost always say whether an animal is one they bred themselves, or if they get them from other local breeders. You can even get a virtual tour of their facilities via their Youtube channel. They also test all of their animals for diseases and I think genetic issues as well. Their prices are a little higher, but if you’re going to be buying from an online seller, it’s worth the peace of mind that you aren’t buying an animal from some random warehouse.