For a promoter, that's a good hustle... Use the money from the opening acts to make back the money from the artists. How much it costs for currensy like $5k? well you made half that back just from opening acts. If you charge a meager $20 all you need is like 150 ppl to make the rest of it back

. I may need to get in the pormotion game
Plenty of artist do pay to open up for x and x artist. The exposure is definitely worth it, some even book the artist themselves and have others artist pay.
think of SXSW and A3C and CMJ...many of those underground dudes with minimal connects for 500-2.5k to open up...Press, blogs, managers, producers, label heads are there. Paying just facilitates your access to connections.
A promoter won't book no name artist or better yet pay them..no matter how nice they are (leave that for the hole in the wall arts centers and pubs)
Think about it, book mid level underground dude (Casey Veggies, hes around 4-5k) plus venue cost. Easily 9k (unless venue splits tickets w you which is wack) and you get 10-15% bar sales.
It's def a tough biz, no one gonna win. Someone will always get fukked.
ps: currency is more like 7-8 maybe more..dude has his own tour bus

. He books his own shows (JET LIIIIIFEEEEE)