If your only interest is serving as an officer in the military, there is no SMC that can offer you the same level of military training and experience that a federal service academy is able to. You need to be fully committed to the task of getting admitted and be certain of the service you wish to serve in. The federal academies exist to produce junior officers for their service - period. If you decide at the end of your 2d year that military service is not for you - you must leave and transfer to another college.
At The Citadel, like other SMCs, you have a much more flexible set of opportunites. This is important as few 17 or 18 year olds know what they want to do for certain. Keeping your options open and having the broadest flexibility is wise. At The Citadel, for example, unless you are on a national ROTC scholarship from a particular service, you have a year to decide which ROTC program you are interested in completing. Also, there are options for serving the country outside military service that may appeal to you after learning about these careers. Unless on an ROTC scholarship, Cadets may choose not to commission in a military service, but remain at the college and complete their degree. This is an important flexibility not available at a federal academy. It definitely is more efficient and cost effective should you decide not to commission.
As for cost, if you are a South Carolina resident, the state lottery merit scholarships make The Citadel a great financial deal. If you are accepted to the Honors Program, beginning in 2017/18 school year, you automatically receive a merit scholarship of up to $10 grand not to exceed your total cost of attendance including any ROTC or other scholarship funds you receive. A new Scholars Program with merit and need based scholarships up to $16 grand, has been added to attract cadets interested in STEM and other majors like Intelligence and Security. The four Engineering programs are top rated, as are a number of other programs, that offer cadets opportunities to serve the country in non-military roles such as Homeland Security and DOD civilian cyber security careers.