Hesitant to sell Because of Tax Hit

[Ron Dulay]

I purchased a property @ $210,000 and after it's said and done, could probably sell for just under $400K w/$25K in fix up costs. 

The problem is, if it is sold in less than a year, I get hit hard with taxes.  I know if it was my primary residence (which it is not), I can get the $250K exemption - Tax Free!  Is there a middle ground?  Real Estate Exchange, but do I get my initial $210K investment back?  How long do I have to keep the property.