Swordfish, this might sound a bit curt, but your question is a bit like how long is a piece of string. There is no such thing as an average commercial pilot. There are commercial pilots working for airlines, air taxi operators, private companies, aircraft manufacturers, develoment companies, agricultural companies, helicopter operators, flying schools etc etc.
There is a huge variation in salaries between companies, countries, and types of flying. even if you added them all together and found the mean average ( and the average often is mean!) it wouldn't necessarily be representative of the area you might be interested in.
Taxes are a deduction that are levied on an individual and vary from one person to another because of the distortions caused by personal allowances amongst other things. Thus all salaries are quoted gross, that is excluding the effects of taxes or other deductions.
If you are interested in any specific area or region a quick search on this site or perhaps a more general search would assist you.