What pushed me to make the jump years ago was looking at how much I was paying in extra charges when I would order for 1 or 2 games at a time.
It was something like an extra $1 per ticket and an extra $10 per order or something crazy like that. A few weeks of spending that extra money really added up and I was able to justify converting all of those extra charges into extra tickets.
You get a slight discount on the actual ticket, normally $24 becomes $20. You only pay 1 processing charge.
I get the seats that I want for every game. Not to mention the ability to go on auto-pilot as soon as I park the car. I know which gate to go to, I know where my favorite concessions are, I know where the closest bathrooms are.
I'll admit, I probably come close to breaking even or possibly even lose some money over the course of the season. There will always be a game or two where I am out of town, or not feeling well, or have other commitments so some tickets go unused.
It is a decision for each fan to make, but these were the factors that pushed me over the top and I've been happy that I did.