Make sure that if you exported with a 'header', that you import with a header as well. Perhaps verification first finds that 'Price' is indeed not valid, as the title row in the spreadsheet is being read when it should not be.

Try this - after exporting your information to Excel, use the 'Autofit columns' in the exported Excel spreadsheet and save with any other changes you make.

You should be able to export alternate price list items and re-import them using the same template field layout.