Wi-Fi sync only works on your home network. It will not "wi-fi" sync when you are on a network somewhere in town, or a friend's network, etc. Both the computer and the phone must be on the SAME network for it to work.
As for the $25, why not this weekend go ask a couple of neighbors if you can mow their lawns for $10 because you need a couple of extra bucks. You do 3 neighbors and you got iTunes Match for a year (and $5 for a healthy Subway meal to reward yourself).
Or if you are minimum wage employee (doubtful), ask your boss for 3 extra hours because you have a bill you need to get paid. You'd be surprised, most bosses will accommodate such a trivial one time request.
Or you can do what I do. Save your loose change. Then after a month or two go to a coinstar machine, pick the iTunes gift certificate option, and then use it toward iTunes Match (it is billed via iTunes account).
I see your point about having something to save up for and not making a lot of money, but if you want something you can find a way to get it. Your budget is flexible enough that if you skip a meal or two out you can come up with the extra cash.
I could understand not wanting to get into a $10+ a month or some other monthly plan that keeps renewing. For iTunes Match, at $25 a year, that's literally
$2.08 per month and it will make your life SO MUCH easier. If you won't spend $2 a month to make your life easier, then, well, you get what you get.
I know what it is like to save up for stuff and "feeling" broke but if you really honestly think about it, your limiting belief about what you can or can't afford is wrong. I know SO many people who often say they won't spend X on this or that, but then go out and spend WAY MORE on something far less useful and important to them and not think twice (eating out or going drinking are the most egregious examples). If you just stop to think about that and consider it, you'd see that your life would be better if you prioritize better.
And for the record, there isn't anything else out there that would be as seamless and beneficial to you as iTunes match. What you'll have instead is some half assed solutions that semi-do what you want but you're going to have to spend a lot of time troubleshooting and stress getting frustrated over.
All I'm saying is it'd just be easier to spend an hour or two on a lazy Sunday morning mowing some lawns and paying for iTunes Match.
