Exact instruction:
1. Go to Items -> Custom Attributes in backend.
2. Click + New Product Attribute
3. Fill surcharge_price_override as attribute code, 'Bottle deposit price' as attribute name
4. Set Custom attribute type as Floating point number and Frontend input type as Text.
5. Save it
Now if you go and edit any product, you will be able to enter the value for a field named 'Bottle deposit price'. The system will take that value instead of the default price of the deposit product.
Note:
surcharge_price_override should not be used for locations or store specific pricing. For that, you need to create a product attribute with code price_<location_id>, you can find location ID in Settings -> Locations section in the backend and make sure location pricing is enabled in Settings -> General Settings.