Tomkins was one of the stars of last weekend's inaugural Auckland Nines as the former Wigan superstar showed glimpses of what NRL fans can expect from him this season.
But he is yet to be tested in the toughest rugby league competition in the world.
Regardless, Tomkins' acquisition has so far been a priceless promotional vehicle for the Warriors in New Zealand and multi-millionaire Watson is impressed by what he's seen on the field.
"He looks great, he looks worth it (the money)," Watson said.
"He looks like he is the real deal. I met Sam a few times when I was in the UK and (Wigan boss) Ian (Lindsay) was very positive about what a great player he could be in the NRL.
"The Nines is his first step, but I don't think anyone would disagree there is something magic when he gets hold of the ball.
"He is very calm, collected, he seems to be able to read the play well ahead of the next play and he talks, he communicates, which is something we really need at the Warriors.
"It is early days, but I am very happy."
Tomkins joined the Warriors from Super League champions Wigan on a three-year-deal worth around $750,000.
Add the $1.2 million transfer fee and the tryscoring sensation is quite an investment.
Tomkins, 24, will make his much anticipated NRL debut for the Warriors against Parramatta on March 9 and is confident his onfield performances will prove he is worth the money.
"I have come here to give it 110 per cent and that is all I can do," Tomkins said.
"I know everything is not going to go my way but I am ready for that.
"I'm sure it is not going to be an easy ride. I know it is going to be a tough challenge, but that is why I came here - I came to the NRL to test myself."
