Still pretty much a newbie when it comes to the genes and breeding, as most of my pets aren't old enough to breed yet.

A lot of the "rares" I have caught have one gene / mutation and don't seem any more rare than the uncommons I have found. They also seem to require a lot more traps to actually catch them, and flee a lot. I have one of the reusable genetic test kits from the diamond shop, and once I see that the pet really doesn't have much, I just release it. Should I spend more diamonds on a scanner so I know what it has before I waste traps?

Are they worth trying to sell?
And are their any pricing guides for buying / selling pets? I'm really not sure what's worth anything and what would be better off getting released.

Any help is greatly appreciated.

I'm wondering the same thing. I thought that catching rares meant a certain number of points, so that the visible ones were two points, and the rest were in carried genes.

Now I'm wondering if the two I caught are worth having caught!

Well, I am a newbie myself, but I'll at least tell you my opinion! I think a genetic scanner from the diamond store is a great investment if you want to try catching Sylesti with specific traits for breeding, and also it let's you see their stats if you intend to use them for questing/arena. You will save so much gold on nets by only going after the ones with the traits you want. The rare may also be carrying genes that might interest you, and the scanner is the only way to know without catching them and genetically testing them with a kit.

as for pricing sylesti, it seems to vary greatly just depending on the person doing the selling. Some seem to just be trying to get rid of unwanted pets, so they are nearly free. Some pets, like fabled species, go for anywhere from 30k-200k depending on how many visible traits there are. I suppose the key to figuring that is to check other people's stables and get an idea for the rarity of the pet you want to sell, and I suppose aesthetics probably play into it as well

That's just my two cents! :-D

Well, until you reach Astryl's Vale, all Rare pets have 3 genetic points, meaning they will have one visible and one carried gene (Once you reach A.V. Rare's have 2gp and can have either one visible or two caried). You won't be able to know what gene the carried one is without a scanner or capture and testing. This can be done by either using a testing kit yourself, or going to the Breeding Discussion forum and having someone there test your pet.

On the topic of being worth catching: If they have genes that you want or are very appealing to you, I'd say it's worth it. If they have a visible gene that is greatly desired by another, maybe. If you're just looking to sell, most likely not, especially if you're looking for a profit. Epics are worth a bit more, especially if they're event ones.

I was battle a rare and I defeat it and gave me a essence.

Defeating any wild pet has a small chance of dropping an essence from that type of pet.