Rocket League2015

Premium currency

You do not pay in euros, you pay in gems, so you lose track of the real cost.

Evidence: Wikipedia (es): «Lo único que será de pago son las microtransacciones cosméticas y otros elementos estacionales que no afectan a la jugabilidad.» · Wikipedia (en): «Psyonix had at one point considered having Rocket League as a free-to-play game with microtransactions, inspired by Team Fortress 2 and Dota 2's models.»

Paid loot boxes

You pay without knowing what you get. The good stuff is rare, so you pay again and again.

Evidence: Wikipedia (en): «In September 2016, it introduced a loot box system known as Crates, where players could purchase them with a random selection of in-game customization items, opened through the purchase of Keys using »

Expiring battle pass

You buy a pass and have weeks to use it. Play too little and you lose what you paid for.

Evidence: Wikipedia (en): «Separately, Psyonix added a battle pass feature to the game in September 2018, known as the Rocket Pass.»

Sold in parts

The full game costs more than the price on the box: there is separate paid content. Not a dirty trick, but worth knowing before buying.

Evidence: Wikipedia (es): «== Contenidos adicionales == A comienzos de agosto de 2015, Psyonix lanzó un DLC para PS4 y Windows llamado Supersonic Fury.» · Wikipedia (en): «As part of a means to monetize the game beyond downloadable content, Psyonix has tried a few different approaches.»