The Stihl 044 and 044 Magnum are very popular chainsaw models. The MS 440 and the MS 441 are the two newer versions since Stihl changed its model numbering system - and the MS 441 is still manufactured currently. You could probably still find the MS 440 for sale new at a local Stihl dealership. In order to purchase the older 044 models, you are going to have to go the used route. For a larger selection, the Internet is going to be your best bet.
The 044 was first introduced by Stihl in 1993. It still is manufactured today in the form of the MS 441. For big professional jobs, this is an extremely popular model and is also in my own personal opinion, very reliable.
For 044s manufactured from 1993, the first year they were introduced to 1999, the 044 has a 70.7 cc engine displacement and 5.1 horsepower. In 2000, Stihl improved the piston and cylinder and the horsepower was increased to 5.4. The 044 is going to weigh about 14 pounds. The maximum rotations per minute (rpm) for the 044 is 13,500.
I found two very nice 044s online that sold for $700 that is a little bit over the odds of what you should be paying for one of these saws. However, there were many models in the $300s that were still in descent running condition. You can see how well the Stihl 044 keeps its excellent resale value when you consider that chain saws being sold for parts or repair are still bringing in over $250.