It's the magic phrase uttered by almost anyone who's ever considered the cost of home remodeling: "We'll get it back when we sell." Unless you keep those projects practical, though, you might just be kidding yourself. For example: Steel front door: Good. Master suite addition costing more than the average American home: Bad. Every year, Remodeling magazine looks at the hottest home upgrades and renovations and calculates just how much owners get back with they sell. [Related: 10 home...