Please help Undefined index?

can someone help me? What did I do wrong? I'm stuck and don't know what to do

{if $event->$value==1}120.000{else}500{/if}

<div class="standard-offers mod">
                                <div class="row" id="row-0">
                                    <label for="offer-0" class="offer-item offer-item-even">
                                        <div class="offer-content">
                                            <div class="vc-image">
                                            </div>
                                            <div class="offer-amount">
                                            {if $event->$value==1}120.000{else}500{/if}                                                                                                     
                                            </div>
                                            <div class="offer-unit">
                                                Dunkle Materie
                                            </div>
                                            <div class="offer-price" style="display:none;">
                                                1
                                            </div>