There are at least 3 timers in the $30 I can recommend----Will Hubin's timers, Ztron and Jmp-2. They all work well.
I got my Hubin timer from Will by dropping him an e-mail--he is registered on this site. The other two are available from a variety of sources---I got mine from
http://www.bsdmicrorc.com/ (look under "misc Electronics".
There are other good timers too, but these are the three I have used. I am sure others will pipe in too.