If you are looking to do a complete kitchen remodeling for yourself, or for maximum resale value, don't neglect the kitchen island. Once just a place to pull up some stools so the kids could eat before running to the bus, the island and it's function in the kitchen has changed quite a bit in the last 10 years.
What can we expect to pay for an island during a remodel? This one is too hard to answer because there are simply too many choices. A "ready to install" stock island you can purchase in a home store with connections for drainage and power can run about $800. A custom concrete countertop island with sink, cooktop, and wine refrigerator can easily eclipse $10,000.
Space and Design are Important : You need around 3 feet of walking space around the island unit, and you must be sure that the drawers and doors in the cabinets have room to open. If you keep to the 36 inches then you should be OK. The only dimension that must be stated is that of the counter height. Ideally it should be the same as the rest of your kitchen units. If not, then it is not a disaster, but can be disconcerting when you are working on the various surfaces at varying heights.
Allow adequate countertop space on both sides (left and right) of the kitchen island if a sink or cooktop will be used. Include at least 15 inches of countertop space on each side, and if your kitchen is large enough, allow even more space. You can never have too much countertop space in a kitchen. Also, rounded countertop corners help protect everyone from bad bruises -- this is true about all kitchen countertop corners.
small kitchen island and bar
small kitchen island and table
small kitchen island with wine rack