Star Trek's massive 50th anniversary convention starts next week in Las Vegas, and celebrities have posted their prices for photos with fans.

Here's the thing about modern sci-fi/fantasy/comic book conventions. Celebrities rarely take photos with fans anymore as a gesture of good will. Actors have discovered that "photo op souvenirs" offer a steady stream of retirement income.

The rules are strict.

At next week's Trekkie convention, photo ops are for paying attendees only. If you pay a celebrity's fee, it only covers you and a buddy. If four people squeeze into the frame, you pay double. And no selfies!

"Your photo will be taken by Creation's all-knowing and super-powerful official staff photographers," the convention rules state.

Also on this restrictive à la carte menu: autographs. And some celebrities will only sign autographs for "gold patrons" who paid an extra fee to attend the convention.

"All prices are per one signature," the rules say.

Resistance is, of course, futile.

Older actors who starred in Star Trek: The Original Series from the 1960s charge higher prices. And the clairvoyant Whoopi Goldberg tops the charts.

Here's are the going rates:

William Shatner (Captain Kirk)

Photo: $100

Signature: $100

Whoopi Goldberg (Guinan)

Photo: $150

Signature: $150

George Takei (Mr. Sulu)

Photo: $80

Signature: $100

Kate Mulgrew (Captain Janeway)

Photo: $75

Signature: $70

Scott Bakula (Captain Archer)

Photo: $100

Signature: " $100 -SOLD OUT"

Nichelle Nichols (Uhura)

Photo: $80

Signature: "prices determined by the celebrity"

Jeri Ryan (Seven of Nine)

Photo: $70

Signature: $60

Walter Koenig (Chekov)

Photo: $80

Signature: $80

Jonathan Frakes (Commander Riker)

Photo: $40

Signature: "at a fee and times determined by the celebrity"

Marina Sirtis (Counselor Troi)

Photo: $40

Signature: "prices determined by the celebrity"

Michael Dorn (Worf)

Photo: $40

Signature: "prices determined by the celebrity"

Brent Spiner (Data)

Photo: $40

Signature: "prices determined by the celebrity"

LaVar Burton (Geordi LaForge)

Photo: $40

Signature: "prices determined by the celebrity"

Gates McFadden (Dr. Crusher)

Photo: $40

Signature: "prices determined by the celebrity"