Do mink coats and other similar types of coats increase in value?

No, they only depreciate with time, as every type of clothes.Fur isn't a diamond, the elder it is, the worse it's condition, therefore--lower price. If you want to get appraisal for the coats, you need contact your local furrier. However, appraisal usually is higher then real selling price.If you want to know real price, you should go on ebay, search for similar coats(age, condition, length etc) nd their selling price would be the number you need.Then you can list your coats on ebay or craiglist.