Being notgeld, I would hesitate to formally classify the Westphalia pieces as "coins", as they lack governmental authority for issue. Notgeld coins are usually classed as "tokens".
Unlike banknotes, coins tend not to suffer from hyperinflationary zerofication, because hyperinflation tends to run too rapidly for coins to be produced - no government wants to spend money to make coins that will be worthless by next week. To get large-numeral coins, you generally need the inflation to creep up slowly, over many decades - as what happened there in Turkey.
"100,000" coins are relatively common; I own some from Turkey and Romania, as well as a 250,000 coin from Turkey - the highest-number circulation coin struck. I have a 200,000 karbovantsiv coin from Ukraine, made shortly after independence; that one disproves the "you need inflation to be slow" theory. Ukraine, like other post-USSR countries, was born with high inflation - they wanted to make some coins to declare their independence, but only had the horribly inflated post-Soviet currency to base their coins on. Needles to say, these Ukrainian "coins" are NCLT.
In terms of the OP's ultimate question, if Turkey is going to be the "winner", then the highest face value coin struck by Turkey prior to the currency reform of 2005 was 150,000,000 lira in 2000, an NCLT bimetallic silver-gold commemorative for Bill Clinton's visit to Turkey. NGC database page. Mintage of just 444, so maybe hard to find?
Unlike banknotes, coins tend not to suffer from hyperinflationary zerofication, because hyperinflation tends to run too rapidly for coins to be produced - no government wants to spend money to make coins that will be worthless by next week. To get large-numeral coins, you generally need the inflation to creep up slowly, over many decades - as what happened there in Turkey.
"100,000" coins are relatively common; I own some from Turkey and Romania, as well as a 250,000 coin from Turkey - the highest-number circulation coin struck. I have a 200,000 karbovantsiv coin from Ukraine, made shortly after independence; that one disproves the "you need inflation to be slow" theory. Ukraine, like other post-USSR countries, was born with high inflation - they wanted to make some coins to declare their independence, but only had the horribly inflated post-Soviet currency to base their coins on. Needles to say, these Ukrainian "coins" are NCLT.
In terms of the OP's ultimate question, if Turkey is going to be the "winner", then the highest face value coin struck by Turkey prior to the currency reform of 2005 was 150,000,000 lira in 2000, an NCLT bimetallic silver-gold commemorative for Bill Clinton's visit to Turkey. NGC database page. Mintage of just 444, so maybe hard to find?
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis



















