You still want to use a block sealer with portland cement before using regular paint.
The block sealer is less expensive (about $30 for five gallons). For a 25 x 28 garage, you may need about 8 to 10 gallons of sealer. After rolling on 1 or 2 coats of sealer, then I would finish with a semi-gloss or gloss paint (laytex is fine) to provide a durable finish.
While the Dry-lock product is about $70 for five gallon bucket, other sealers are much cheeper.
I would also all the mold inhibitor to what you use for the final coat. Its only $2 or $3 for some added protection.
The block sealer takes some effort to roll on. Put it on thick, using a 3/4" nap roller. You will cover about 1.5 blocks every time you load up the roller.
If you decide to paint the floor. Make sure that you clean it with muric acid first. I would use epoxy paint on the floor.