It may have been a frustrating day for him against Reading on Saturday but Trevor says: "I don't think I would swap him with anyone - not for that money, anyway!" he says.
With David and Jermain Defoe - rated in the high eight figure bracket - on four goals apiece, the former's relatively small fee is looking like a bargain.
But surely, David isn't worth, say, 50 times less than Jermain?
"I wouldn't even think about what his value would be because he is not going anywhere and we wouldn't draw that conclusion," insists Trevor..
"I think you can say he is worth a bit more than we paid for him at the time and also he has got some good players around him which I am sure he appreciates as it gives him the opportunity to express himself, just like Jermain is doing.
"Although those two have been putting the ball in the net, apart from Christian on Saturday, I don't care who scores as long as the whole team is contributing and we have the spirit to carry us through the months ahead.
"David is excellent, a natural goalscorer who links play well, and there is good rivalry with Jermain.
"They will get a lot of goals between them and there is the option of Neil Mellor, who is a lovely lad with a different style and a really good attitude - he was unlucky on Saturday.
"But we are extremely lucky with the trio of strikers we have got to choose from."
David says he is hoping to play for the Republic of Ireland against Switzerland in the crucial Euro 2004 qualifier next month, following his man of the match performance and spectacular goal against Turkey in a friendly last week.
He collected a pass from Liverpool's Steve Finnan, cut inside Aston Villa defender Alpay on the left after outpacing him, and slotted home at the near post.
"Hopefully my performance will get me into the side for the Switzerland game - it is a huge match and it is one everyone wants to be involved in," he says.
Trevor adds: "I was going to say it would have done David's confidence a lot of good by scoring but if you know him you know doesn't need a boost to confidence because he is that sort of individual.
"It was a top quality goal and the pleasing thing was he did it against a top quality side like Turkey.
"David is not always first choice for Ireland and it shows what he is able to do and puts pressure on for the selection next time round.
"They have an important game with Switzerland soon and if David continues to do well for us in the next three weeks he could well be pushing for a starting place."