LEARN GARAGE SALE DOS AND DON’TS Dear Heloise: Two weekends ago, I went to a garage sale, and the lady who had items for sale didn’t have a price on anything. When I asked her how much she was asking for a couple of nightstands, she said, “Make me an offer.” I did, and she flew into a rage because she felt that the offer was insultingly low. I have a few hints on the do’s and don’ts of garage sales that might avoid anger and confusion for both the seller and the customer: Have a price sticker on everything you’re selling. The “make me an offer” approach usually makes people decide to walk away…