how to display the suffix of the field? Display the suffix for the field 'price', i use:

&lt;?php
print $node-&gt;field_price['und'];
?&gt;


but only it render the value without the suffix ($)
You should ideally be using the render functions to output the stuff in content and node arrays in Drupal 7, the reason you are not seeing the suffix is that you are simply pulling out a value and not rendering.

So the following should work for you:

&lt;?php echo field_view_field('node', $node, 'field_price'); ?&gt;


Take a look at Drupal's reference on field_view_field and this article too