Hi Anne,
If your customer is going to pay through Paypal, you don't have to worry. Paypal will automatically convert the money according to the conversion rates for today. I had a customer from Norway and there was no fuss- Paypal converted the Krone to Dollars and I didn't have to do a single thing.
Your customer should be able to check out normally - you shouldn't have to change your listing at all.
I hope this helps! :-)
Best regards,
Lysirra