MySQL: preferred column type for (product) prices?

Decimal is the one I would use

The basic difference between Decimal/Numeric and Float : Float is Approximate-number data type, which means that not all values in the data type range can be represented exactly. Decimal/Numeric is Fixed-Precision data type, which means that all the values in the data type reane can be represented exactly with precision and scale.

Converting from Decimal or Numeric to float can cause some loss of precision. For the Decimal or Numeric data types, SQL Server considers each specific combination of precision and scale as a different data type. DECIMAL(4,2) and DECIMAL(6,4) are different data types. This means that 11.22 and 11.2222 are different types though this is not the case for float. For FLOAT(6) 11.22 and 11.2222 are same data types.

Field type "Decimal" is good.

If you have highe prices then you can use product_price decimal(6,2) NOT NULL, i.e. you can store prices up to 6 digits with decimal point before 2 digits.

Maximum value for field product_price decimal(6,2) NOT NULL, will store price up to 9999.99

If all prices are between 0.01 to 25.00 then product_price decimal(4,2) NOT NULL, will be good, but if you will have higher prices then you can set any values in decimal(4,2).