Yes. Super-Krete applications are popular for overlaying existing formica, laminate and tile countertops. However, it is important to remember that the substrate that Super-Krete is coating must be structurally sound. Super-Krete will transform virtually any sound substrate into a masterpiece.
The price per square foot will be dependent upon the application, color selection, texture, existing surface conditions, and many other factors. You will want to get a quotation from the installer who will know how to properly estimate your project. In most cases, however, the cost to "Super-Krete" is much cheaper than removing and replacing concrete with plain, dull concrete.
Efflorescence is typically a sign that an excessive moisture problem exists and the problem must be addressed. Remove the efflorescence by scrubbing off the white deposits (soluble salts) with a stiff broom, high pressure washer or an appropriate cleaner. Do not use an acid-based cleaner.
After the efflorescence has been completely removed, apply Pene-Krete concrete treatment. Pene-Krete sealer will reduce moisture vapor emissions without leaving a surface residue and will keep efflorescence from recurring.