Depends on the parts and year model you are looking for...if it's the latest model, then I think its quite expensive and you have to buy it directly at your favorite dealer. Been sourcing some parts lately and I was surprised to hear that Banawe is more expensive than the dealers price. This is because they also source the parts from the dealers themselves and they have to consider also their margin.
Ford Classic is a good car and even if the car is discontinued Ford will keep its parts for at least the next decade. In comparison to Etios it may be an old car but it can easily match Etios performance and comfort. Though, if you are planning to buy any one of these we will suggest you to wait until Ford launches its next car, the Figo Aspire. Know more about Ford Aspire: http://www.cardekho.com/carmodels/Ford/Ford_Figo_Aspire
The has been no such announcements from Ford motors on this. So the model is not being phased out in near future. But, yes eventually the model would certainly be phased out, but when is that going to happen is not certain.
No matter a car discontinue or not, the manufacturer makes the parts available for a good 8-10 years after it is being discontinued and as manufacturer uses the same engine in multiple models, there is a higher probability that you can get engine parts easily.