Sanitize all except number, forward slash and $?
<p>I have an entry form for 'price', and want something like:</p>

<blockquote>
  <p>$250 full price /$230 early booking</p>
</blockquote>

<p>To be sanitized within the database to:</p>

<pre><code>250/230 
</code></pre>

<p>Or </p>

<pre><code>$250/$230
</code></pre>

<p>Is it possible to do either in PHP? </p>

<p>I've tried:</p>

<pre><code>$formdata = ( isset( $_POST['price-entry'] ) ? sanitize_html_class( $_POST['price-entry'] ) : '' );
</code></pre>

<p>But this strips everything except letters and digits. </p>
