Through the Roof?

So I've been trying for a while to get a quote for a new HVAC system for the house. Because the house is small, and interior space is limited, rather than taking up space on the inside of the house with a new furnace, and space in the backyard with a condenser, I've decided to opt for a more expensive, albeit more space conscious roof top unit (rtu). I just today received a quote from the more impressive of three HVAC company reps which has come out to look at the project. The first to come out, while he seemed knowledgeable, couldn't put a hard and fast number to the work I wanted done, and was reluctant to provide the type of system that I wanted, which signaled to me a certain unfamiliarity. However, the second person to come out was by far the worse. An HVAC contractor which is an approved contractor for Home Depot, this fellow not only seemed to be a bit overwhelmed with scope of the job (a full install), but also didn't seem to know a whole lot about what he was say, from the assertion that a condenser unit alone for my small house would weigh 500 lbs. to the fact that he didn't know what an 'rtu' was. Fortunately the last guy to stop by was very familiar with the type of system, and had actually installed some similar units in Georgetown recently. So his experience and knowledge alone set him apart. The quote that I received seems to be in line with what I was told by the first guy: $13,700. While this is about five to six thousand more than the price of a split-system would cost, I still can't help but think that this is the right way to go.