Any expenditure of real-world money on a game, beyond that required for basic access to the game (subscription fees or expansions), is a microtransaction. One could argue that a one-off expenditure like a ship unlock is more akin to an expansion, but if it becomes the norm to acquire such access piecemeal, I'd consider those microtransactions. A repeatable purchase like a pre-built ship is every bit as much a microtransaction as cosmetics, if not more so. Cosmetics after all, are infinitely reusable and can be duplicated (put on more than one suit/vehicle) without needing to be bought again. A pre-built ship is a discrete asset that must be purchased again to have another copy of it.