Okay, my question is... what are you wanting to use these for? Highly concentrated flavorings like this are usually used in making large batches of carb foods, like candy, cakes, muffins.
Which you totally aren't making if you're here. ;)
If you want to give a little citrus flavor to a chicken thigh, or a bit of spice to a salad dressing, these are going to be HORRIBLE because they're WAY too intense for such a small application.
And -- as someone mentioned before -- citrus zest, spices, herbs, etc. are all generally cheaper, easier to find, easier to use in appropriate moderation, and are okay on most any variation of Primal/Paleo diet.
(And yeah, everybody's up in arms about PG, but the extract is probably only using PG as an emulsifier to get the flavor oil mixed into an alcohol-and-water base. And when you consider that these extracts are used by the drop or quarter-teaspoon in multi-serving recipes, you're talking about extremely small amounts in a serving of food. Yes, of course, the purists will avoid any amount at all costs, and hey, great for them... but nobody's drinking cupfuls of the stuff. I have an extract I use about three drops of, about once a month, and that's in a six-serving recipe. I have a hard time freaking out about that low a dose, especially when I'm still working on avoiding much bigger monsters in my diet. YMMV.)
But yeah, if you really need to use extracts, and want to avoid the PG, get the pure flavor oils and either mix them with oils and fats directly, or choose your own emulsifier (egg yolk, gums, etc.) as you cook with it.