Talented filly Lady Banff was the cheapest buy among trainer Matt Dunn's yearlings this year but she could turn out to be one of his best.

Lady Banff ($2.80) jumped straight to the lead and was too good in beating Mary Valley ($3.70) by a length with 2-3/4 lengths to The Silver Lady ($16) in the Two-Year-Old (1110m) at Doomben.

Dunn had some inside information on Lady Banff when he went to $40,000 for the filly at the Magic Millions March sales.

"I trained her dam Alberta and she had a lot of ability but also some mental issues," Dunn said.

"This filly has none of those issues and she had trialled well coming into today. I was a touch worried about the 1100m today and I had thought about waiting until next week for a 900m race at Newcastle.

"But she has shown a lot of pace today and I liked the way she went about things in the straight.

"I think Lady Banff was the cheapest yearling we bought this year and she has already repaid her purchase price."

Lady Banff is by underrated sire Top Echelon who traces his bloodlines back to champion galloper Gunsynd.

"I like the Top Echelon breed and Lady Banff should get a bit further on her breeding," he said.

Lady Banff is eligible for the Magic Millions 2YO Classic and Dunn will now have a think before committing her to the race.