How to add else if to my existing php code?

I have a piece of code that lists a certain custom post type on wordpress. I'd like to change the "price" section in the below code with the one I've added below. The 2nd piece of code works on another page, so it should work here as well, but as this is written in php, I can't manage to add it. I tried to remove the php beginning tags but the code won't work no matter what. It's probably a silly question but I'm a newbie so any help would be very much appreciated.

Original code: (The "price" part should be changed with the one below)

<?php

$str .= '

<!--start preview-->
<div id="'.$post_id.'" class="grid '.$atts['post_grid_columns'].' percentage nicdark_masonry_item nicdark_padding10 nicdark_sizing">
    <div class="nicdark_archive1 nicdark_bg_white nicdark_border_grey nicdark_sizing ">


        <!--start image-->
        <div class="nicdark_focus nicdark_relative nicdark_fadeinout nicdark_overflow">    

            <img alt="" class="nicdark_focus nicdark_zoom_image" src="'.$image_attributes[0].'">


            <!--price-->
            <div class="nicdark_fadeout nicdark_absolute nicdark_height100percentage nicdark_width_percentage100">  
                '.$outputpricecurrency.'
            </div>
            <!--end price-->


            <!--start content-->
            <div class="nicdark_fadein nicdark_filter greydark nicdark_absolute nicdark_height100percentage nicdark_width_percentage100">
                <div class="nicdark_absolute nicdark_display_table nicdark_height100percentage nicdark_width_percentage100">
                    <div class="nicdark_cell nicdark_vertical_middle">
                        <a href="'.$permalink.'" class="nicdark_btn nicdark_border_white white medium">'.$alldatas['metabox_package_linktitle'].'</a>
                    </div>   
                </div>   
            </div>
            <!--end content-->

        </div>
        <!--end image-->


        <div class="nicdark_textevidence nicdark_bg_'.$alldatas['metabox_package_color'].'">
            <h4 class="white nicdark_margin20">'.get_the_title().'</h4>
        </div>


    </div>
</div>
<!--end prev-->

';

The code I'd like to add instead of the original "price" section:

            <!--price-->


<?php if( has_term( 'firsat-paketleri', 'duration-package', $post_id ) ){ ?>
 <div class="nicdark_fadeout nicdark_absolute nicdark_height100percentage nicdark_width_percentage100">  
                <?php echo $outputpricecurrency; ?>
            </div>
            <?php } elseif ( has_term( 'grup-turu', 'duration-package', $post_id ) ) { ?>
   <div class="nicdark_fadeout nicdark_absolute nicdark_height100percentage nicdark_width_percentage100">  
                <?php echo $outputpricecurrency; ?>
            </div>
<?php } else { ?>
   <div style="display:none;" class="nicdark_fadeout nicdark_absolute nicdark_height100percentage nicdark_width_percentage100">  

            </div>
<?php } ?>




            <!--end price-->