as a general rule for me, runs themselves should pay 1000-10000 per character depending on the difficulty (10k runs are essentially suicide missions for all but the best runners)... however the run payout is far from the only way to make some cash, which is one of the biggest reasons I dont have the runs themselves pay more, frugal players will find many ways to make extra money... if it's in the barrens or other similar area... practically anything and everything they see during the run that will fit in a vehicle, will be in a pawn shop by the next morning... bikes from gangers, every gun, every jacket and piece of armor, every commlink, everything... including any "recently used" cyberware if they can get the bodies to a safe place, and if they can do the run fast enough the bodies themselves may get donated to science

make sure you use the rules for buying / fencing... read through them a couple times, without a face character they're probably looking at buying anything for 130% book value, and selling anything at about 25-30% book value (make sure to include mods, that secondhand cyber is 30% of the cyber value, its 30% of the secondhand cyber value )
if it's in a better area where they can't take the time to rummage you can still expect them to grab weapons, credsticks and commlinks off of dead or unconcious guards, etc...
if it's in any kind of corp office and there's a decker involved you can pretty well bet on them trying to sell off some corp secrets for extra money.
point is, the run itself is the last of your problems if your players are semi-intelligent and greedy
remember, it's just as easy to make the run harder by throwing in an extra 3-4 guards high on jazz, as to add a cyber troll with big weapons.... and when the players win, the 4 dead goons will mean less money than the cybertroll with expensive toys