Craigslist is a great place to pick up used splits. A lot of the time with skins. Also look for used rental boards and demo fleets. They do exist out there. I believe NOLS blows out a bunch of splits every spring. At least they used to. They were a steal. Splitboard.com is another place to pick up great deals on splits. This goes for Splitboard bindings too.
Unless you have some serious alpine objectives, ski crampons are probably not needed to start with. You'll want them at some point, but since you are new to this you shouldn't be putting your self in those sort of spots.
The tough thing is that yes, this is a fairly big investment. Seems to be around $1600 these days for a good splitboard kit new. Then if you need the avy gear, there goes another $300-$600. Don't buy a used beacon, unless you know the previous owner and are sure it is up to snuff.
Snow shoes do work, especially if you have spots you can hit that are relatively easy to get to and lap. It'll also make you come up with the money for a split set up that much faster. It's amazing how that motivates people.