Please note, that this issue took place in power query editor, not in Excel application side.

Product and price rows are of text type. Price should be numeric field, that calculations could be carried out with price row.

After changing the row to decimal number, the row shows an error.

This issue can be tackled with query options.

Select file – options and settings – query options.

Take regional settings – locale.

As the decimal separator was a dot, the local settings should be changed to English.

Now the data type can be changed.