The resale value of the bike may not be there as Honda stopped making the cr125 in I think 2007 and are not producing any more. You would get around 70mph out of one.
A two stroke engine mixes oil to lubricate the internal moving parts of the engine with the gas. The mixture is sucked into the carburetor and mixed with air. A four stroke engine runs on gas by itself. The oil is contained in the crankcase.
