I guess this would solve it (well, a meta tag instead of h2 of course), but, I want to learn more codebehind ...
<% if (CurrentPage["SiteSeekerWeightPROP"] as string == "1")
{ %>
<h2>Weight: 0.1</h2>
<% } %>
<% if (CurrentPage["SiteSeekerWeightPROP"] as string == "2")
{ %>
<h2>Weight: 0.2</h2>
<% } %>
<% if (CurrentPage["SiteSeekerWeightPROP"] as string == "3")
{ %>
<h2>Weight: 0.3</h2>
<% } %>
and so on ... to 0.9
<% else
{ %>
<h2>Weight: 0.5</h2>
<% } %>