What makes you think I don't buy wards? You can only buy two wards at the start of the game, and buying two wards and the courier upgrade all by yourself before the first creep waves is just ridiculous.
Really though what are you saving the 200 for, fast boots? The courier is needed anyway so might as well get it sooner rather than later.
I play support assuming I'll have to do it all myself -- which is usually true. So go all out and play smartly. You'll benefit your team and better still you'll learn to play better with minimal items. Some games will REALLY suck because you are literally itemless, but when you finally find someone who helps you support you'll feel like you can contribute so much with a few items.
Final note to all the above: Don't pick hard support if you have a gut feel that your team is retarded. You'll just hate yourself when your carry can't actually carry you when you could have just dominated as a strong mid, or sidelane carry.
P.S. minor totems are the best way to fill out the inventory when you're done buying!