Can I pull a recruit down if he's already considering another school?  He tells me I'm a backup.

yes. sometimes it seems to be a little more costly though, but usually its still the same old 10-12 evals.

yeah, I'm on 30.  Should I give up?

Its taken me over 40 before.

dont give up if you have the ability to get other guys too.  at one of my D3 schools i had a transfer guy that i put 28 sv's into and he wasn't considering me.  finally after putting in 2-4 SV's for several cycles in a row he shows up as considering a D1 school.  4k down the drain.

anyway that school ended up signing other players and i put one more SV into him and got him, and he signed the next cycle. 

unfortunately i've also had the same thing happen where i end up running out of money...but nothing ventured nothing gained.