For nearly two years, home buyers have been shopping in conditions ripe for regret. Prices have soared, inventory has plunged and competition has been brutal in markets across the country. With fixer-uppers fetching multiple offers, buyers must make snap decisions about what is often the biggest financial investment of their lives. Invariably, someone makes a choice they wish they hadn’t. “There are all kinds of craziness happening,” said Marilyn Wilson, a founding partner of the WAV Group, a consumer research company, who described open houses so crowded they felt like nightclubs, with buyers getting 15 minutes to tour a home. “Sometimes people don’t remember, did it have three bedrooms or…