Summoning up: math skills.
Suppose we've got a 2nd-level wizard, with 500 sp to spare.
Prep an abandoned barn: two big wood cages, one over the summoning circle, one where the wizard stands. Should be able to do this for 100sp
That'll leave enough to buy you 20 orphans or cripples... or, if you're playing something sorta Thirty Years War, just capture some refugees. Tie 'em up, gag 'em, pack 'em into a barn, get the whole actual party outside.
65% chance of blowing the initial save * a 1 in 20 chance of rolling the 8 Real Bad Things. By my count, most of these aren't so bad if there's just one person present, in a cage, with a team to check on them in an hour: only #3 seems definitely lethal in those circumstances.
With the +20 atrocity bonus, it'll be very very hard for the demon to beat the wizard; even if it does, there's still two cages to get through. Very very likely that you'll have a pet demon- at least for a year and a day.....