Free members can't even get to the page unless it's Happy Hour.
Graying out some of the options won't help on the CPU expense. The expensive part is the search-word list. Everything else on that page is so inexpensive it's free for all practical purposes.
A lot of my work on it recently has been to make the whole thing less expensive. Mostly testing different methods, and I did find one that cuts the cost by about 30%, so I'll use that one.
Oh, the "by" bug is fixed. If any words were shorter than 3 characters, it wasn't checking to see if they were "noise" words.
I'm going to add a few more features, get the Private Message search working, then call it done.