Repair the picture-check button, broken by a $-quote in patch text

A literal $' in replacement text is consumed as a special pattern by the
patch API, which truncated the block mid-string and swallowed the
if (unfilmed) line with it. BROWSER_TESTS.md records this exact hazard.
The price is now built by concatenating the dollar sign separately so no
$-quote sequence appears in patch text at all.

trailer.html

@@ -423,7 +423,11 @@
             + '" title="Samples frames from every clip and asks what is wrong '
             + 'with the picture, then whether it matches the script.">'
             + (es === "ready" ? "Check the picture again" : "Check the picture")
-            + ' · 
+            + ' · ' + "$" + (filmed * 0.02).toFixed(2)
+            + '</button>');
+      }
+
+      if (unfilmed && !undrawn)
         out.push('<button type="button" class="btn primary" data-film="' + esc(meta.id)
           + '">Film ' + (filmed ? 'the ' + unfilmed + ' remaining shots' : 'all ' + shots.length + ' shots')
           + ' &middot; $' + (unfilmed * 0.75).toFixed(2) + '</button>');