Are the programs made for off site events worth collecting? I know they don't value as well as on site programs,but are they still collectible?

On site merchandise is always more collectible, but some of the off site memorabilia such as programs and posters are also collectible.

I went to the De la Hoya v Mayweather fight earlier this year, couldnt get an actual fight ticket so got the next best thing and watched it on a large screen in a marquee, on my way back to the main casino i picked up a full fight ticket on the floor, i thought `You Lucky Ponce`, but then I found out that all the tickets will be full because they used a bar code on them and an electric scanner to read them...
but hey its still collectable

It could be a forgery; how can you verify its authenticity?

not sure, havent seen any others for sale yet.....

Lucky you!