Handanovic will cost minimum 15m eur, even if 20m is quite fair for him.
Milan do need a good goalkeeper but Berlusconi will pay for a GK only if it's Buffon or Casillas. Otherwise he won't give a single penny. In the last 20 years Milan had around 20 goalkeepers and they only paid money for Storari (1.2m eur), Dida (1.55m eur--3 billion lira), Fiori (0.3m eur), Rossi (0.4m eur) and Lehmann (1m eur).
Milan will keep Abbiati until he starts making mistakes. After that they will replace him with a cheap option.