The Citizens splashed out £278m on nine players during 2017-18 campaign, including £57m on club-record signing Aymeric Laporte in the January window.
Guardiola acknowledges that a similar amount cannot be spent next term, though, and is happy with just a couple of additions to bolster his Premier League-winning side of 2017-18.
"[We will sign] one or two more, no more," he told Sky Sports News. "We cannot invest... maybe people don't believe me but we don't have the money to invest £300m every season.
"We invested a lot of money and will invest less in the future, because instead of doing it in two or three transfer windows, we did it in one. We needed it for the age [of the squad].
"The fundamental success of this season is the quality of the players. People say you won because you invest a lot, they are right. Ederson, for example, was perfect, but then at the end you are saying 'go and try the Premier League and try to play' and you don't know if it's going to happen."
City ticked off a number of records in winning the English top flight this season, such as most games won, most points gained and most goals scored.