There's a couple of things to consider.

1. Is the old house in a G&G area? How about the new house?
2. Is the cost of the old house + renovation fees much higher than the new leasehold house?
3. Would RM150k renovation + RM100k to furnish the house be a huge burden, compared to just spending around RM100k to furnish the new house?
4. Typically, developer offer huge discounts on downpayment and legal fees (most of the time it's zero nowadays). For the old house you'll need to fork out around 5% of the price for stamp duty, legal fees etc etc. Have you taken this into account?