I have owned both 2 stroke and 4 stroke engines. I prefer 2 stroke. Fuel economy for 4 stroke is about double the 2 stroke, BUT you will have other issues such as old fuel left in the tank, water in fuel, etc. etc. If you think carefully, then it may be easier and cheaper having a 2 stroke! sadly now I have a 4 stroke!
In addition to what other have said:
2 Stroke:
You CAN and WILL enjoy doing DIY jobs on it
4 Stroke
Need to take it to main dealer, especially with new engines having ECU (like car engines need diagnosis computer)