They cost more to Develop and to build per unit, but (again, done right) over their lifetime would be much cheaper. The major failing of the shuttle program was not so much the direction of the program, though there were of course areas that needed improvement. It was all of the "hands in the till", the massive number of contractors, staff and facilities spread across the US that were deemed "necessary" for the program. The actual costs for the shuttle specifically (parts, labor, fuel) was quite small, and considering it was built in much fewer numbers than originally intended, almost competitive with expendable launch systems. With today's tech we could pretty easily develop a "stage and a half"/"two stage" craft that could fly at least a dozen times before requiring minor overhauls, and probably 50 flights between major overhauls. But to really bring down the costs they would need to be built on a modern airliner scale (hundreds or +1,000 of them) & politics would need to be kept to a minimum (no shipping fabrication of certain parts to Vermont to keep their Senator happy when a plant is ready to produce them cheaply in Missouri). A SSTO craft would not be out of reach, but would probably require much high development cost. Either case though is a "chicken and the egg" problem, for it to be economically reasonable there would need to be the drive to flight thousands of flights a year, a market for thousands of flights a year will only come into being when the flight costs come down massively.