Here's what I've experienced in the Big Mango, having lived in many accommodations. Apartments in Saphan Kwai, Samsen, Huay Kwang, Sukhumvit Soi 10, and On Nut. I've also lived in a shophouse near Sathorn, and now in a Townhouse near Sathorn.
Electricity in apartments tends to be between 5 and 8 baht/unit
Electricity in shophouses or townhouses is at between 3 and 4 bath/unit
My water bills have always run at about 500 bt/month regardless of where I've lived.