For single-player in-game transactions? Personally it doesn't matter, as long as there isn't any leaderboards and you're not flaunting anything online. It's technically cheating, but if the game is onerous without the cheats then it's a poorly-designed game and deserves to be cheated. If you're not affecting anyone else with the cheats, then go for it.
Unless it's an idle game, in which case the prices are designed to be onerous to waste your time and keep you playing so you don't jump to the next game quickly. And if that's the case, why are you cheating in an idle game?
It's not an idle game, but yeah single player in game stuff. Like the player has to buy or "win" a piece to upgrade their ship, but it takes 300 pieces to do it. Or they let you watch an ad to get a chest with game pieces - once a week .