Exact cost of a project depends on the specifics.   Here are basic prices to give you an idea of budget.

Event Videography (Memorials)

Shooting: $350 for the first hour. $150 each additional hour. (Plus expenses such as parking.)
Post-production: $75 per hour of labor. The amount of time depends on amount of editing, extent of titles, number of revisions, etc.

Tribute Movie

Depends on the number of items included and whether or not there are interviews and travel.
Price starts at $500 for a five to 10 minute program.