I have found fragrance oils at Walmart. The ones I get at Walmart are like 2 ounces for $1.97 - they are good for oil burners and to make your own reed diffusers. They can also refresh potpourri, but you will have to do it more often as they are a little weaker in scent.
www.wellingtonfragrance.com sells fragrance oils and I did a review on their site. I like the customer service and what they sell. Now - they have a lot of "plain" fragrance oils like sandalwood, patchouli, anise, heliotrope, geranium, ginger, ylang-ylang, pink peppercorn, etc so that you can build your own fragrances. They also have some premade fragrance mixes.
When purchasing fragrance oils for soap, bath, body - make sure they are for that exact purpose. Some fragrance oils sold are just for inclusion in candles or to place in oil lamps, etc and not to be used in any body product.
Essential oils can be used WITH a base - like almond oil, grapeseed oil, etc. Never use essential oils on the skin directly - they are too strong. Also - check on the oil you want to use. Some women that are pregnant, have epilepsy, etc need to stay away from certain essential oils. (That is why I like to stick with fragrance oils)
You can find oil bases in wholesale and health food stores. They may be a little on the expensive side -(but should be under $10)- and they last a long while.
You can try Micheals, Joann's, and other craft places like Pearl if they are still around.