Ok, I can't count how many times I've been playing Cyberpunk and the entire plot got derailed because some meathead player shouted something about taking all the guys they just killed off to the body shop for some cash. Hoping to get on with the plot I say, okay fine you get X Euro per body, let's move on. Next thing I know, it's all about dragging bodies to the chop shop. Or in Underground, players KNOW that virtually everyone is a body donor to Tastie Ghoul so the same thing happens even though they aren't related they try to collect the cash (which is such a small amount that it's hardly worth the effort). Players are always drunk with the dreams of cold hard player cash and what it can buy them.
Ah but now GMs have a weapon to combat this evil headed coinage. Wealth and purchase DCs are awesome. Simple to deal with, not a lot to keep track of. Players don't have to balance their characters check book each game session. The focus of a Cyberpunk game should not be on how much cash the character has and what they can sell the dead bodies for! I think this system will help put the focus back where it belongs; on the role-playing.
As for how much to pay PCs for a mission... Wealth seems to be pretty much all inclusive. It assumes that you do whatever you have to in order to have the Wealth level that you do. Going on jobs to collect a package would already be factored into your Wealth level because it is jobs just like it that allow you to have it that high in the first place. As for grabbing all the gear and junk of the dead, again I expect that's already a part of your Wealth level. If the PCs are sent on something that's going to be a stretch for them, then I strongly like PsycloneJack's idea of giving out CredSticks that offer Wealth Bonuses and all purchases subtract from that until it's depleated. An awesome idea that I plan to us in my games.
So, it seems to me that it's better to have this kind of system rather than actual monetary values. Without them players still like to pick up equipment and such, but they're less likely to turn it into shopping list gaming where it's all about how much cash you're earned and what it can buy you. After all, money is a tool of the System, and the System is no friend to a True Cyberpunk.