You can purchase reagents from the Bazaar in Olde Town, from specific Reagent Vendors or you can also find them through creature drops or discovery of the items in the worlds.
The trade of items between different account logins will not be added to Wizard101.
The only items that can be traded between two different account logins are non-enchanted Treasure Cards.
Items that you want to place in the Shared Bank can be moved between Wizards on the same account. If you can't use the item, sell it to the Bazaar, and if it is marked No Auction, you can sell it at the regular shopkeeps throughout the Spiral.
If you want the prize, you have to build the ladder rung by rung. There are no shortcuts.