If you guys could go ahead and restrict the use MBs while being on another world

[Lmcgyver]

Have not read all 11 pages of responses so apologies if this has been said already. I think that since they've opened up the buy function from all servers on a data center they should just open it all up. Make the MB data center wide for buying and selling.

As a programmer who can take a pretty good educated guess at how the system works, I can see a very good reason why this is not currently possible. Each server would maintain its own files for each player, and for market listings, all it really has to query is its own database whenever a player searches the market, and it only has to verify purchases within its own database.
The reason that buying items is perfectly fine is that, upon temporarily transferring to another server, a small portion of the player's data is copied over - this is the same data that is transferred to instance servers, allowing you to use your inventory and obtain loot during a duty, and is returned to the home server once you transfer back.
This data allows that server to handle market interactions by that player as it would with any player on the server. There is no need for communicating or verifying the transaction with other servers, it just handles it itself. All of the framework for cross-world buying by visiting was really already there, it just needed a way to use the duty finder to connect two main servers together (i.e. World Visit).

Cross-world selling, on the other hand, is a far more complicated process. Either a) a central server that is dedicated to handling the market for every player on the datacenter is introduced which every server would need to communicate with for all retainer summons and dismissals, market searches (incl. price checks for item listing) and market transactions, or b) every server would need to query every other server for its market listings whenever a player searches, and would need to verify cross-world purchases with the other server.
In both cases, a lot more load is introduced, both on the servers themselves and the connections between them, not to mention the additional coding overhead needed to implement such a system when the servers have been developed over several years to be more-or-less self contained, only sharing minor information with other servers for instances.
There is, however, another possible method for cross-world selling, using the existing framework like they did with buying; namely, transferring retainers along with the the player. This would, however, have the drawbacks of allowing only one world to be sold to at a time, as well as additional overhead in transferring the relevant data.

TL;DR: There was likely very little work nor overhead involved in making buying things from a visited world an option, whereas selling things to all worlds is a much more complex problem to deal with involving massively increased server loading wherever the market is concerned.

[Musashidon]

Then why restrict selling?

since this was never answered

because the sever couldn't handle it, they wanted to have the whole thing open up and be shared but it stressed the server too much and had to be put on hold.

Make the MB data center wide for buying and selling.

seems everyone ignored to say in this thread at all that they did try to do a full buy and sell but it over stressed the servers and had to be left with buying only atm.

[SamSmoot]

No thanks. I like being able to flip things from other worlds. Besides, cheaper things on smaller worlds is good for newer/poorer players.

I don't like the flipping. Takes too long. Just combine all the linked world MB's into one, so you see everything for sale without having to change worlds.