I bought some Phillips CF lamps in about "91 or so, the sticker on them was $45.00 each, I sorta know the store owner and he let me steal them for $14.00
Today the best or cheapest place to get them is at Sam's Club.
The come like 6 to a pack for about $5 each more or less.
I use them in bathrooms cuz the heat generated by incandescant bulbs causes cooling problems in the summer.
Also I break the rules and use them outdoors in "Carriage" fixtures for lighting up the walkway, it's suprising how much light a 15 watt bulb produces when you line the fixture with aluminum foil in every direction you don't want the light to shine
In the master bath, I've unscrewed all of the 5 bulbs but one cause it was a waste, the single 15 watt is more than enought light for me.