Today, a dishwasher is an expected appliance and a MUST have. It would not be uncommon to lose a potential buyer because of what is really such a minor issue. My opinion is most definately, yes, on the dishwasher. If I understand your question correctly, to install it will cost a total of $2,900.00 including all electrical service, plumbing, changing cabinet configuration, and the unit itself. To me, it is well worth the investment. In this case, with the installation of a dishwasher, you're not overspending for the neighborhood -you're keeping in competition with it. I think you're wise to consider this, and on the right track to making it the most saleable in the future.