bullshit. theory & practically it's totally different. you calculate the ingredents like 4gc for LE, 14gc for srs etc etc.
i thought the same as u as i started summoning... lvl 40 costed me ~1.8m gc and even at lvl 50 i made a loss, at lvl 53 i complained because i lost 4/10 spiders, and i also lost 3/10 bears which are no profit at all, not to talk about tigers which were a pain in the ass.
20 le, 100gc
4 srs, 56gc
1 wtf, 80gc
20 gypsum, 60gc (hyperbag)
296gc + feasting = 302gc (no fails calced) + 4 fails if your lucky out of 10 (lvl 53).
profit? fuck your calcs, even with 1 crit fail you'r making a loss already.
oh well, the first kind of profit i got was on mid 50's with spider stones, tigers with 60 and up even though the gc sucks.
now back on topic: summon stones suck, but if people wanna use them it's their decision not mine. i'll take MD exp wherever i can.