Sir Lancer engines are very expensive, if you have the old dolphin shape Lancer, 4G61 will cost you more than 50K Rs.
For the yellow cab shape Lancer, I once saw the 1.6L V6 engine for 60K Rs.
Also try to find the 4G15 12V, best for your budget.
Look for engines in good shape, most shopkeepers will try to sell you the Corolla engine.
Must get a compression tester as advised by Xulfiqar bhai, very good investment for any car owner.