Never heard of them. They appear to be a travel agency marketing consolidator flights, since it seems they only quote prices by phone. You might ask them who the consolidator is, how your card will be charged (by the airline itself is safest) and which airline's "ticket stock" the ticket will be issued on (should be that of the overwater carrier).

The agent should also review the ticket restrictions and penalties with you, as well as their own agency service fees, so you know what to expect if you need support prior to or during your travels.