I would go with the Ella.

The Ella is the cheapest of the three your mentioned, and has incredible reviews. A lot of women have found their g-spots with her, and the silicone is an easy material to get used to. She has just enough give to have give (unlike the pure wand, and, from what I hear, the Comet G). Furthermore, she has two sides, and though I know everyone seems to hate the "traditional" side, I kind of like it when warming up, just for a bit so that I feel more "open".

All three of these toys have a learning curve (as do most g-spot toys), but the Ella might be the one that helps you find your g-spot the easiest, since it's form is more meant for easy finding. Granted, your anatomy might not fit it, but the same can be said about the other two as well.

The pure wand would be my second choice from that list, but I feel that it's expensive and not quite meant for beginners. Don't get me wrong, it's incredible once you get the hang of it, but it might be too cold / unfriendly / heavy for you as a beginner to work with. I admit, I'm buying a pure wand and it's coming in the mail later today, but I still intimidated about using it.

If you're just going based on reviews, the Ella does have incredible reviews virtually everywhere, unless, of course, she doesn't fit your anatomy. Granted, I've heard of less people hating the Pure Wand than the Ella, but I'd still try the Ella first. Silicone is a much friendlier material, and she's a lot lighter and easier for beginners to use. I think, if you were an advanced user asking this question, I would have said pure wand, but as a newbie the Ella really is a good toy that has found a lot of women's g-spots and given many of them their first squirt, whereas the pure wand is often a toy they get afterwards and once they're comfortable with their g-spots.