The problem is in the sunk cost. If I were to play fairly aggressively, collecting 8 times a day, from a girl that gave $1500, (pretty average), for 365 days a year, I would have gotten 4.38 million. Now, there is no way I'll see that much, but suppose I did. The cheapest cost of affection per game dollar is legendary lingerie at $417 per point. I have my 70th girl at 2 stars and to get her the third would require 10,645 affection. Some might be free, but not all will be in it's cheapest form, so I'll just use that cost. So it will cost me 4.44 million just in affection for that one. If I'm crazy about collecting, I just might recoup that in a year, but that isn't the whole cost of the upgrade.
Now I have to look at how many years it will realistically take in collections for the girl to pay for the upgrades I put on her. With cash becoming tight in the game, it becomes a poor use of resources to pay for affection and for the upgrades. You just have to decide how much a loss you want to accept.

If you think this is a good deal, let me sell you an annuity that pays back it's purchase price at twice your life expectancy.