Price will vary for the same quality material from dealer to dealer, so it pays to take some time and visit several shops before making major purchases. Also, you are not qualified to do an appraisal because you are emotionally attached to the collection. The place to start is your local rock dealer. For a fee, many are willing to make a written appraisal of your collection. To get the highest appraised value possible, you must have the collection well organized and cataloged properly, otherwise the appraiser may waste a lot of time and not see everything in the collection.
Appraisals are extremely important to have.
The only way you can get an insurance policy rider on a collection of rocks and minerals is through an appraisal by someone the insurance company considers a competent expert. Only rarely do we encounter a rock or mineral thief, but the odds are relatively high that some natural disaster will affect your possessions during your lifetime. It could be a flood, fire, tornado, hurricane, or perhaps simply vandals. If you had to liquidate a collection, selling the best pieces for a premium price to individual selected collectors will get you the most money. No collector I know.