I am looking to expand my army but my budget isn't that good. I know that both terradons and chameleons are very nice units but which one is of higher priority. IMO I would prefer the terradons (3 of them) than chameleons (6 of them) because I already have 2 units of 12 skink skirmishers. However I have never used any of the two in my army so I dont have any experience. What do you suggest?
Use your skink skirmishers as cameleon, proxy them. Try a game or two with them and see what happens. Then proxy your terradons and try a game or two. See which you like better.
Personally I find chameleons to be better now. I usually take 7 of the little buggers and try and scout them nice and close. First turn you can usually double shot on 5's to hit. Terradons get a nice vanguard move and then can usually be behind enemy lines on turn 1. The only problem I have is drop rocks seems less potent in this edition and they get much much fewer shots. Both can be good options and end up costing around the same points. Just play test them and see which you prefer.
Both serve quite the same role in the army but do that in a very different way. I find chameleons to have a bit more staying potential but terradons have better movement and are a bit better in close combat. Now that you have 2x12 skirmish skinks maybe you could reduce your unit sizes to 10 and then convert the spare 4 to chameleons or maybe simply by painting them differently. You would just need one more somewhere and then get the models for terradons. I use normal skinks as chameleons. I have just paint them to stand out so they won't be mixed with normal skinks. I never drop the rocks to bigger units these days. I try to find some more suitable target for them. Maybe some small skirmish units or fast cavalry. Units that have low or no saves are the best. Sometimes I even drop rocks warmachines too and hope for 6's. But this is only if I can't charge because of intervening unit or something. BR Agrem
This is true. My chameleons are just normal skinks with a slightly different pose (as far as that is possible) and a whole different color scheme. They stand out more than enough for my opponents to understand that they are not regular skinks. Terradons are still good. Most opponents have at least sóme chaff, like fast cavalry. And Terradons>(horseback) fast cavalry. So you can target the light units effectively. After that, go after a war machine, the (very) odd lone mage or just redirect. Against a very weak combat unit, you can even rear-charge them for a +3 combat resolution swing (rear+charge). Very effective.
It kinda depends on your opponent too, to some extent. Terradons are quite expensive, but they can fly over obstacles to get at warmachines or silly people who don't attach their Mages to a bunker. Camo Skinks are cheap, and can't be shot down before doing their suicide drive-by (they set up 12" away, double tap), but they can be constrained by clever deployment of the enemy force (ie shielding approaches to their warmachines to prevent your unit from being in range).