I always run my dishwasher last thing at night, on a programme that doesn't have drying. When it's finished I pull out the drawers and leave the dishes to drip dry overnight. Unload them the following morning. This cuts down the expense.
It's a german one and came with a booklet giving lots of info - how much water each cycle uses, how long it runs etc.
I don’t know have any estimate with the cost for each wash but it is better to go with the dishwashers. It can save you so much of your time and energy. You can keep all the dishes and clean them twice or thrice a week altogether depending upon your needs. Initially I found it hard to manually wash my dishes but then with these dishwashers, things became easy. Especially the portable dishwashers are very useful. You can buy them at 100 to 200$. It’s worth your money you are investing on them. Find about different dishwashers here http://www.theportabledishwasherreviews.com/