Wordpress Custom Fields

If the price is stored in a custom field in the post where your Gravity Form is embedded, you can set the default value for the field by using this merge tag:

{custom_field:[name]}

If your price is stored in a custom field called "ica_pricing", you would use:

{custom_field:ica_pricing}

as the default value for the field.

You can use the gf_readonly approach to keep the value from being edited.

Please post a link to the page on your site where we can see a form, and let us know what information is stored in the post custom fields which should be populating the form fields. Only custom fields associated with the page or post the form is embedded in will be used.