Receiving spice for revivals while not paying for revivals themselves seems out of line. Compare it with the Empire receiving payment for treachery cards or the Guild receiving payment for shipping. In both cases they must still pay the cost (or part of the cost, in the case of the Guild) when they take the action themselves.
No idea if the faction is unbalanced as-is, but that struck me as odd.
The fremen dont pay for revivals and most factions revive some troops for free. rarely does the atreides or harkonnen ever revive more than 2 troops per turn.
Early on the bene tleilax do struggle. There is usually less combat in the first few rounds and therefore less revivals. In play they tend to be very agressive, trying to kill other players troops and usually targeting the emperor or the guild due to the fact that those factions only get 1 free revival. Ontop of that their 30 ghola troops only have 0.5 strength but still cost the full amount to ship. The money they get from revivals is spent quickly on shipping and treachery cards. They lag behind both emperor and guild in wealth which is exactly how it should be. But they can become formidable later game much like the bene gesserit.
There is never a dull round with the bene tleilax in play.