The 2 out of 5 rule does not apply in your situation, this is a sale of a rental property, not personal residence. Your basis = 223,200 + 2,550 - Accumulated Depr for the building plus the FMV of the land on 8/2012. Passive losses are taken on Sch E and do not go into your basis calculation.
Yes, sales price- commission - basis = gain/loss. But since you are dealing with depreciable real property, a portion of your gain will be section 1250 gain taxed at 25%.
I would worry about anyone only charging $300 to prepare this return.