The Brazilian moved to The Hawthorns from Sporting Lisbon in August with the Baggies initially paying £775,000 to bring him in on loan.
But that deal gives Albion the right to purchase the player at any point for £8.25million – with Pereira having already agreed personal terms for his permanent transfer.
With the 23-year-old having been in spectacular form this season, the Express & Star understands the Baggies will take up that option.
And Bilic feels Pereira represents outstanding value for money.
“Yes – if we get promotion,” Bilic joked when asked if Pereira is a snip at £8.25million.
“No, you’re right, Pereira is a bargain anyway.
“But it’s still early days. He also has to stay focused and lift the bar.
“Sometimes he does too many sexy things.
“But is he good? Yes, he’s good. Very good, I love him, but he has to be even more ruthless.”
Bilic revealed how he first discovered Pereira – with the head coach admitting the scouting process can at times be painstaking.
“Pereira was on loan at Nuremberg last season and I have many friends in Germany,” he continued.
“I played in the Bundesliga and my ex-assistant from West Ham (Edin Terzic) is at Dortmund and we are basically in daily contact.
“In the transfer window he asked me about some players, I asked him about some players.
“You are watching players every night. I don’t know how many. That’s why I hate the transfer window – seriously because for 10 hours, eight hours, a day you are watching players.
“It’s fun the first day but after a few days you can’t wait for it to end.
“You need it, of course, it is crucial, without that you are dead basically.
“But on the other hand, you can’t wait for it to finish because there are too many players to watch.
“I watched Pereira a few times and he looked top in a team that got relegated.
“I remember watching him in games in February when there is snow around so it’s not like Brazil, but he looked great.
“They were losing but he was the one that was telling saying ‘come on guys’ and all that.
“It was not only his quality, but the attitude and mentality were correct as well.”