They can almost certainly get it to price out on one ticket. But OP should just be aware it can often cost more than simply buying two separate roundtrips, or an open-jaw booking with a separate one-way. As noted above, it would be helpful to know what type of fares (coach? business?), budget, and actual origin/destination/dates to come up with some examples. If you use Google Flights to price out multi-city, it will actually advise you when it is cheaper to book on separate tickets instead of a single one.