Some old code causes this issue in your Shopify settings, and is very easily fixed. To fix the pricing display issue, please do the following:
1- Go to this page in your Shopify Admin: https://shopify.com/admin/settings/general
2- Scroll down to the "Store currency" section
3- Click the "Change formatting" blue link.
4- Find the "Email with currency" and "Email without currency" fields (see image):
5- Change the "Email with currency" field from:
<span class="money">${{ amount }} USD</span>
To:
${{ amount }} USD
6- Change the "Email without currency" field from:
<span class="money">${{ amount }}</span>
To:
${{ amount }}
7- Once done, save the changes.
Note: It may take 15-30 minutes for the Order Printer app to reflect the changes made to the settings above.