Having no Special Input at that time (Maybe a bit later), I just want to throw into that - while fluid in development- the idea`s seem appropriate at that time. They surely Need to be balanced between Intention/Goal, and actual causality and Impact on Players and economy, balance the pros/cons of that and being willing to make changes and Adjustments.
As for the 5 Item Limit and the Fee on Bidding. No one knows how this would work out, really, in matters of how pragmatic it is (beside the Intention to “Keep the flow and balance within the market” vs. “what is the Player experience and how does this Limit to ensure the market is functioning Limit the Player experience”. I can see how this makes sense, I can see how this can lead to Frustration too.
Let`s say you want to get rid of your Sorcerers gear, and your Druids gear, and get into making a powerful Lich. With a 5 item Limit, you are heavily restricted time-wise. Not knowing how it may turn out in real-game, as a Player experience. I mean, you can create Problems by simply trying to avoid “that and this” Problem - e.g. botters, spammers, inflantation, etc. and therefor making a System inherently unfun or ineffective to use, or ineffective to use for certain things.
I mean, this is probably where in-game trading may be a possibility, or another function where you can “send out” that you sell full Sorcerer and Druid Equipments (probably 20-30 items in total), and People can whisper you or something. 5 Limit restriction, with its potential or theoretical inherent Pros, can have theoretical or practical Con`s, that could be or could not be dealt with at some Point, through additions or alternative Solutions.
Another idea, within the 5 Item Limit, could be: 5 Trades can be set on, that People can bid for. E.g. I offer 3 items, and I offer 2x2 sets. That is 7 Items total, but only 5 trades People can bid. So I can put online 3 items, and I can put online (on the Bazaar) the Equipment of my Sorcerer and my Druid, for a valid high Price to bid for. It will Count as 1 item, because it is 1 trade, but it includes each for example 10 items. You cant bid for one, but only for the totality.
Or you can enable that you either have a Limit of 5 Items, or you have 2 “listings” instead. Items will be directly on the Bazaar, meaning that Players can search for it by searching for specifics (e.g. “helm - strengh - vitality - minion resistance”. These will Show in the market and Count to your items. You can have 5 items max.
A listing would constitute of lets say 3 items, and it has a Topic. E.g. “Melee Sorcerer Item”. People can then go to “Listings” instead of “Search for Item”, and the Listing constitutes of “General”, and then one for each Class. So 6 sectors, General - Mage - Rogue - etc. You can choose whether a Listing will have 1 Price, or if it can be bid on each item. But for Purpose, having a listing have 1 Price would be better, because you can list more, but that should be the downside Maybe. Sell the pack or you dont sell the pack. Otherwise, sell the item. As a buyer, you also have the choice: buy an item or buy a pack. Packs could come with the downside that you dont Need all of the items. But then again, it makes more sense to put items in a pack that align with what People generally Need together (e.g. Melee sorc items), and the rest sell as items.
Ideally you could make the max. items on the Bazaar 6. One pack could hold up to 6 items. You can choose to sell 6 items or 2 packs total. One pack equals 3 items on the Bazaar. So you could e.g. list 3 items and 1 pack, or 2 packs, or 6 items. Pros: items can be searched for directly and bid for individually. Cons: Costs time and is limited highly, but more efficient in selling for particular Prices, and in a certain pace. Pros of packs: can sell more items at once. Cons: can not be searched for directly, can not set Price for items individually hence takes Maybe more time to sell
Since other matters have already been discussed full and frank, such as BoA etc. - one has to see how the middle-way turns out. That everything is tradeable to Long-on-the-F-list-People, could make it. I like both! But Im both a Trader and a “find it yourself-er”. So, from both standpoints, I wouldnt want be too restricted in both ways. To an extent. Just, finding an Ultra rare item you wouldnt use because you would never Play a melee sorc feels bad. Getting a super cool helm for your summoner that you couldnt find in months as a trade-off feels awesome though! The Question then would Maybe be how one can balance the trade-Offs of both sides, instead of causing bad Symptoms because you try to “avoid something” with a Concept design - but entirely creating a new Frustration therewith.
You could also add a function to BoA. E.g. destroying an item that is inherently BoA ( versus e.g. items that are BoA through Crafting) could give X amount of Gold, or this or that of high value. So that finding a very-rare-hard-to-find BoA item is NEVER a “no-win-situation”. And thats the Point. Or being able to re-craft a BoA item. E.g. find a BoA Helm for druid. I dont Play druid. You can reroll the helm to turn into another BoA helm. Maybe you are lucky! But some mechanic could be added to not makeultra-rare BoA`s into a Frustration-funnel.WHen you finally find that item that you dont Need at all. 
Hyped for the beat and to try it out!
Cheers1
