Hello,
This is my first attempt to an EDH deck, I'm still missing several "important" lands, and also the guild gates will have to disappear.
The commander is Crosis, the Purger and the theme should be dragons, goblins & friends (friends because I don't own many cards to have other goblins, dragons).

I also have few cards that I could put in there but at the moment are in my standard deck.

http://deckbox.org/sets/397933

I would like some feed back on which cards to cut and which cards to add/substitute without paying too much for them.

Thanks!

Only card that I'd really question in your deck is your Hoarding Dragon and that is more due to your selection of artifacts. The only artifact in your deck worth hunting down knowing i'm going to have to wait for it is Mindslaver. all of your other artifacts are mana fixing and therefore fall into two categories. Ones you don't want to wait around for like Chromatic Lantern or Sol Ring and ones that are past their usefulness like Lotus Petal once you have enough mana to cast the dragon. Sure you have Dragon's Claw and Elixir of Immortality bot neither of those are things i'd want to weight around for while i look for something to kill a 4/4.

Krenko, Mob Bossdoes seem just a touch out of place in this deck. While your deck does get some benefit out of goblins, you only have 4 in your deck and Krenko tends to die a quick death as other players view him as a threat because of his effect. He works best when you can have several goblins on the field before he arrives. He also greatly benefits from Fervor so he can do some goblin doubling before someone kills him off.

Actually just about anything benefits from Fervor and it's probably not a bad addition to this deck.

Aside from that the only thing that really jumps out at me is that you mana curve seems to be going the wrong way. you've got a lot of very expensive creatures, though that is common in dragon decks. I think i'd personally add in some utility goblins to help smooth out the curve some but i do like the flavor of a Dragon deck.