For cells to propogate in serum free medium there have to be a few growth factor and mitogens (PDGF,FGF,TGF-beta etc).You will have to coat your flasks with either gelatin,fibronectin or collagen since there is the absence of serum.It is difficult for you to make a cocktail of your own and will turn out to be expensive.
You should try Mesencult-XF-SFM(Stem cell technologies) or Stem PRO-SFM.You can also give a try to Nutri-Stem(Biological industries-Israel).
If the main issue is the cost of the serum you can prepare (Platelets human lysate) which is added in the media to replace the commercially prepared serum.