Unity 5 Saving and Loading variables - save

Question

i know i can save int,float,string with PlayerPrefs, but how can i save a boolean too, like the Player has money, and he is bought an upgrade, how can i save if the player bought the upgrade and load it next time?
I have my upgrades like this:
public void Computer()
{
if(tier1 == true && Click.money >= cost)
{
Click.money -= cost;
ItemNameInfo.text = "[TIER II]Computer";
UpgradeInfo.text = "Wooaah! Upgrade Time!\n(Gives +5 CPS)";
cost = 1000;
costInfo.text = "Cost: " + cost;
Click.moneyperclick += 1;
tier1 = false;
tier2 = true;
}
else if(tier2 == true && Click.money >= cost)
{
Click.money -= cost;
ItemNameInfo.text = "[TIER III]Computer";
UpgradeInfo.text = "It's still isn't good enough\n(Gives +10 CPS)";
cost = 20000;
costInfo.text = "Cost: " + cost;
Click.moneyperclick += 5;
tier2 = false;
tier3 = true;
}
}

Answer 1

You cannot save bools to Player Prefs.
I tend to just use an int.
For example, let's say we have an item "item1".
To check if the player has that item unlocked:
if(PlayerPrefs.GetInt("hasItem1",0) == 1){
//player has item 1
}
to unlock item1:
PlayerPrefs.SetInt("hasItem1",1);