That's the artist Van Dyck, not the actor Van Dyke. Sounds the same though.
For nearly three decades the BBC had produced a programme called Antiques Road Show, in which antiques experts tour the country, and in prime locations film them examining and valuing people's treasures. I believe it also exists in other lands - Canada, Australia, possibly the US too. Certainly they have done "specials" from those places and achieved a following.
Occasionally they find a total gem of exceptional monetary value. One such was the rare slipware jug Ozzie the Owl, who sold for over £20,000:
A few months ago a priest brought in a painting he had bought for £400, hoping to find it was worth more, so he could sell it to get his church bells replaced. The experts thought it just might be a lost Van Dyck, which would make it worth rather more than the man thought.
Turns out it is - and it may be worth £400,000! Much restoration and research seems to reveal it might be a sketch for a group portrait that was destroyed hundreds of years ago.
Don't know about you, but if I gambled £400 on an art work, it would turn out to be worth 40p!