Games typically don’t cost more on Xbox One compared to Xbox 360 and PlayStation 3. For example, Call of Duty: Ghosts costs $60 on both of Microsoft’s consoles. That cost parity doesn’t mean developers aren’t going to try to get more money out of gamers.

Five different Xbox One games at launch will feature free-to-play-style in-app purchases, and only one of these games is actually free to download and play. These are Ryse: Son of Rome, Forza Motorsport 5, Powerstar Golf, Crimson Dragon, and Killer Instinct.

Out of those five titles, only Killer Instinct is a free download. Players can get it for free and play online with everyone else, but they only have access to one character and one stage. Fighting fans can then decide to either unlock the entire game for $20 or individual characters for $5 each.

The way Killer Instinct does things is actually kinda cool. What’s less cool? Well, Forza 5 costs $60, but you can spend up to $100 at a time for special in-game currency to unlock cars faster. Developer Crytek’s Ryse: Son of Rome is another $60 game that will sell you special in-game gold for real money.

Powerstar Golf and Crimson Dragon, on the other hand, are only $20, but they both feature alternative digital currencies that you can pay for. Crimson Dragon will sell you 45 “jewels” for $10, and Powerstar Golf has credits you can buy and then spend on randomized loot (although those credits aren’t for sale in the Xbox Games Store yet).

Why are so many of these games implementing digital currencies? Well, because humans don’t associate financial anxiety with virtual money the way we do with cash in our pockets or the balance of our debit cards.

“If real money was used — no successful game developer does this — then the consumer would see their money going down as they play and become apprehensive,” game designer Ramin Shokrizade wrote in a blog for Gamasutra in June. “This gives the consumer more opportunities to think and will reduce revenues.”

And it’s all about generating that revenue. Another thing you might notice is that all of the games using these free-to-play monetization tactics are published by Microsoft Studios. A Microsoft spokesperson told GamesBeat that this doesn’t signify some sort of mandate and that developers decide this sort of thing on a game-by-game basis.

None of this is to say you can’t enjoy games like Forza without spending extra cash. I enjoyed it, but I started to get that creeping suspicion that maybe the devs are trying to manipulate and play me so that I’ll spend money at certain points. That Lexus LFA sure is gorgeous, and it only costs how many tokens?!

I can’t prove that developer Turn 10 made changes to its game to increase the likelihood that I would spend more money, but proving it isn’t the point. The suspicion is enough for some people.