I have just left Liverpool after 2 seasons in charge- I sold £105m worth of players and bought £106m. If you're careful in the market there is no reason why you can't get decent signings.
Additionally, if you can prove yourself, then more money can come your way.
I finished 4th in my 1st season and won the FA Cup. The board then asked my expectations for the following season- I said title challenger. I then won the league and FA Cup last season and the board then gave £33m to spend for my 3rd season (I resigned before pre-season as the Brazil job came up and I fancied a crack at international management but didn't want to do both!).
Also, furthering what others have said, it's true to life and we all want realism in our games. And if you don't like that, change it!