The 21-year-old Brazilian winger became Silva's first transfer as Everton boss when he joined from Vicarage Road last month in a deal which could rise to £50m.
The Toffees were criticised in some quarters for shelling out such a hefty sum on a player who has not scored since November, but Silva pointed at the example of Jordan Pickford - who joined the club for £30m last summer and went on to become England's number one at the World Cup - as evidence that such deals can prove to be value for money.
"I can speak to you about what happened one year ago when we took Jordan Pickford and everyone was talking about it at that moment," Silva told reporters.
"Now no-one is talking about his value. The value the club paid to take him here is normal in football. The market now is really difficult.
"If the player will perform well and do the best to achieve our goals at the end no one will speak about the price."
Richarlison could make his competitive debut for Everton during their Premier League opener against Wolverhampton Wanderers on Saturday evening.