Hi all interested in this topic,
as promised I come up with a summary of what I have found out in my researches. First of all, let me tell you: DO YOUR HOMEWORK properly before you get the License itself. Sounds ridiculous but in fact it saves you from running into difficulties.
Freezones: FZ's offer a variety of opportunities FZ Co, FZE, FZ LLC, Freelance work. The major advantage is the 100% ownership. A disadvantage is that you are officially not allowed to do business outside the Freezone or set up an office on the mainland as the FZ isn't considered to be in the UAE. Depending on the content of your business keep this in mind.
Mainland LLC: Your partner (local sponsor) is the key to success. There are several types of licenses 1.commercial, general trading, professional|services.
If a professional|services license suits your business (for certain professions like doctors, lawyers etc.) you can own it 100% too but you have to appoint a local service agent (almost like a sponsor). There is no tax in general BUT you pay 5% of the rental contract yearly on top. Then you are fully liable with all your assets!!
The form of an LLC reduces your risk (as the name says it).
The license costs can be looked up on the department of economic development website which provides good info. You can also go there, line up and talk to a competent person there.
If you want to buy a second hand license, before you put the money on the table: thorough check on visas taken on the license, loans hanging on to it etc. Make sure it is a good product you buy!
Incase you make a fresh license: depending on your business calculate between 12.000,-+Dhs. + visa costs + notarization of MoA etc. Then you actually know how much money you have to take in your hands to hit the market.
That was all for now.... time to get professional
Wish you all a great Iftar today....