I almost tempted to buy a lot of lightings from lighting.com at Jalan Besar. The sales person sales pitch that theirs is only consuming 36Wph for 2 tubes of 36W on those ceiling lightings due to only 1 ballast, in series connection. Some more electronic ballast, once turn on, no flickering. Then, I was enlightened by Denny from Extreme Lighting in Balastier.. Everyone else is selling these ceiling lights with 2 magnetic ballasts. Although this means that the lighting will consumed 72Wph as you turn it on and there will be flickering when u turn on. why?? The reason is simple: magnetic ballast will outlast electronic ballast based on the usage. So, if you want lasting lightings, should take magnetic ballast for bedrooms and living room, since you will not switch on/off often. On the plus point of 2 ballasts instead of 1, if one light bulb burnt, the other bulb will still work due to paralel connections. You will not have to live in the dark. You'll have time to replace it.
Yes, lighting.com lightings are 110% cheaper, but not lasting..