It would be interesting if there were more things in daily life that cost money, not just luxury objects, although that’s a good idea too.
I'm thinking taxes for instance. If you have Get To Work and Discover University, that goes to pay for the hospitals and schools (according to my country's economical plan, health care and all education is free for all).
I use the money the sims can get from University as a symbol of the student beneficial sum+loan to pay for living expenses; and not as a charge for the actual education.
The lot taxes are a little confusing to me, what they are for; but I like that they are fixed and that bigger costs more. I like the additions of bills that came along with EL.
The game is undoubtedly made to be very easy for reasons, so I don’t think they will remove the option to buy groceries through the fridge, although that would be a great area to expand on, costwise. Some foods are very expensive; where I live it is the fast food and the ecologically grown that are comparatively expensive, besides luxury ingredients of course. I really like the political policies in the conservationist career, those should be developed! I don't think the actual political career will get them in a game made by EA, but to sneak more in somewhere else, and more to the point of politics, that is, economics, would be great.
There are also some great suggestions of rearranging the price levels on the things in BB mode on this forum; although I get that the idea of being able to buy a rocket ship is silly enough to fit the game's theme. To add mortgages for home byuing too, and take out loans etc. These features do not need much in the way of gameplay to add the realism that many players want, it can just be a little option on the phone.
Edit: I of course very much like the idea of the NAPs from EL, but there are just a few I actually will use, like Free Love; because the effect from them are mostly idles, and influence points, that are unnecessary, being more of a one time thing to have need for. They would serve as a great plattform to build on.
