You can still purchase every cosmetic item offered by Aelonwy Maelodic using the in game shop and a little crafting.

First, go to the in game store and purchase a number of Top Hats. The exact number required will vary depending upon how much Glammerdust you already possess and what cosmetic item you plan to make. Take your Top Hats to Aelonwy Maelodic and ask her to turn them into Glammerdust. She will exchange each Top Hat for 10 Glammerdust. Once you have enough Glammerdust, talk to her again and this time trade the Glammerdust for the item you desire. Most items cost 40 Glammerdust. Assuming you start with zero Glammerdust, this equates to 4 Top Hats (150 x 4 = 600 DDO Points).
If you pursue this endeavor, I highly recommend waiting for a game shop sale on cosmetic items and thus Top Hats. During a 50 percent off sale, the price of most cosmetic items offered by Aelony Maelodic effectively drops from 600 DDO Points to 300.
Please note, you can still play the game for cosmetic items from Aelonwy Maelodic. Level normally. In the process, you will acquire Favor and DDO Points. Most cosmetic items from Aelonwy Maelodic effectively cost 2,400 Favor since 24 x 25 = 600 DDO Points. If you can wait for a 50 percent off sale, most of her wares effectively cost 1,200 Favor.
If you go the Favor route, acquire the Favor and thus the DDO Points in advance of a sale. Do not try to acquire all that Favor during a sale. Most players simply cannot muster that sort of leveling speed. Collect your DDO Points in advance of the sale and exercise enough discipline not to spend them.
Obviously, the developers never intended the Gold Coin barter option to exist. Someone made an unfortunate mistake and it was corrected. While I feel your pain and lost 200 Gold Coins because of what happened, I also understand the position of the developers. I intend to take my own advice and stockpile DDO Points, through purchase and Favor, in advance of the next cosmetic item sale. That was my plan before this unfortunate mistake. Effectively, nothing changed.