Be aware, the conversion of a dining room to a bedroom requires very little material investment. Where the value will be derived is turning a house with an obsolete floor plan into one of contemporary design. A kitchen with eat-in space, although it sounds wonderful, does not make it contemporary and most likely limits it's appeal to N'eaterners who are accustomed to archaic design.
Have a real visionary or a contractor or a REALTOR evaluate your homes potential. Integrated seating, open architecture, flex space are all elements of contemporary design and may be accomplished for less than you think.
It is possible that adding a bedroom, strategically located on the 1st level, can add value if there is demonstrated market for extended family living. Most folks however, will find a bedroom located where the DR formerly existed, will not be considered strategically located.
Now, regarding the DR/BR issue, to avoid creating even greater obsolesce, one must ask, "How big is the garage or parking provisions?" 4 Bedrooms eventually leads to no less the three drivers. Nothing hurts neighborhood values like cars parked on the front lawn.