Credit card installment payments are very convenient. To be able to have something now and pay later (multiple payments) is always good, but this privilege needs to be handled with care or it will hurt you. We will use one of my recent transactions as an example.
This is my Montblanc Tribute to the Mont Blanc Series 149 Le Grand fountain pen. I bought it from the Montblanc store in the Rustan's Department Store in Makati City. It was a lifetime investment, since a Montlbanc fountain pen will last a lifetime (and because it was so expensive). Installment payments are designed to help us acquire things of this nature, especially when very expensive and intended to last for a long time.