If your son/daughter-in-law to be have over the years been exposed to quilting, your son might surprise you by really appreciating the love, time, effort (and yes, money) in your gift. If it's heirloom quality I'd say get an appraisal. I gift a lot of quilts, some of which I wish I had had appraised but I confess: I want my quilts used, hopefully for years. God bless their marriage and lives together