The currency symbol is not always obvious, depending on the currency you are working with. The symbol for Costa Rican Colon, for instance may not display correctly or the same. It may have different appearances in the same R session, and cannot be included here because they lead to built errors.
get_currency_character(currency_value, currency_symbol_pos)A single value from the currency column
The number of positions from the left for the currency symbol (include any spaces)
To have a check in place you can request the first character of the currency strings with this function, and use it either to assign the currency value, or to do a sanity check.