Q:

Adding a #suffix to a Drupal Product Form Payment Method Radio

I have two radio buttons in my Drupal 7 product form. One for credit card and the other for 'send an invoice'. I'd like to add some text after each option but I don't know how.
In my hook_form_alter module this is what I'm attempting:
$form['commerce_payment']['payment_method']['#options']
['paypal_commerce_payment_paypal_wpp']['#suffix'] = 'text here';

However, this keeps throwing an error:
Warning: strlen() expects parameter 1 to be string, array given in 
drupal_validate_utf8() (line 1599 of 
/var/www/checkout/includes/bootstrap.inc).
Notice: Array to string conversion in format_string() (line 1550 of 
/var/www/checkout/includes/bootstrap.inc).

And under the two radio options it just says 'Array' next to yet another radio button. Obviously not what I want. I want the text 'text here' to appear right after the 'Credit Card' radio option.
I also tried targeting the 'suffix' with '#field_suffix' to no avail.
Any idea how to make this happen?

A:

The issue here could be the type of element $form['commerce_payment']['payment_method']['#options']['paypal_commerce_payment_paypal_wpp'] is. 
Is paypal_commerce_payment_paypal_wpp the key of one your options? 
Have you tried #description?

