@_Sandra_
It's more about gameplay value, than in-game cost vs realism. There's basically no challenge. My new sim is making thousands per day just by creating and selling paintings. 1 painting paid for the entire term.
But yet, we have to deal with the house rent skyrocketing because we purchased ideas like new lamps, or renovated something simple like a closet. We can't even keep and store the items we find around the worlds because of this added expense which isn't shy to include our inventories as well.
IRL when was the last time your property tax bill increased because you purchased a bunch of pictures for your wall? Or, placed some nick nacks on a couple new shelves?
University however, something that DOES imply a high cost IRL, especially here in North America, and places like the UK the sims' team decides to package it all up into a DLC that offers no gameplay challenge.
I could create a new sim as we speak, and have more than enough money to achieve university simply by catching fish in my free time. In just 15 minutes I found a few trinkets in the Sulani world that I sold for nearly 400. I wasn't even trying to find stuff. I went to make a coffee and didn't pause my game. When I got back minutes later, my sim had found by then 3 items from digging in the sand. If I would have decided to make a sandwhich with my coffee she may have found the entire uni-term cost right there. Where's the challenge???