Using <strike> or <del> in a select box
<select>
    <option value="1">Small Box 10.99</option>
    <option value="2">Large Box <del>19.99</del> 15.99</option>
</select>

"19.99".replace(/d/g, function (digit) { return digit + "u0336" })

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<!-- The style in the span tag is completely ignored -->
<option value="1"><span syle="color:red">Small</span> Box 10.99</option>

<select>
    <option />
    <option value="1" disabled="disabled">Small Box 10.99 (Original Price)</option>
    <option value="1">Small Box 6.99 (Sale Price)</option>
</select>