Just a possible explanation, but I notice you've used a comma where you've written "5,00" in your post. Perhaps you did that when you were filling the price in? It's a bit of a leap, but am I correct in thinking English isn't your first language?
The reason I ask is because I know a lot of languages use a comma as a decimal point. In English we use a full stop to write the decimal point and commas are used as the separator every thousand in large numbers (i.e. $5,000,000 is five million dollars).
But that separator has no actual mathematical meaning and is probably ignored by computers, so writing $5,00 is the same as writing $500 rather than $5.00.