We have both a dehydrator and meat slicer, probably both are used 90% for jerky making. I have occasionally dried some veggies and herbs, but jerky seems to be its main use.
Here are a couple thoughts, things I have found, might help you decide on what you want or if you want one.
I would say the Excalibur is definitely the most trusted dehydrator on the market.
We have a less expensive model (I think its this one http://www.amazon.com/Nesco-American.../dp/B003I4F7EY). The only thing that I find the biggest pain with making jerky is trying to get the trays clean afterward, but its really not that big of a deal if I let them soak for a bit. Oh, and ours doesn't have a timer, so I use one of those simple plug in timers you can get at a hardware store for a few bucks.
As for a slicer, we got one from bass pro half off on a black friday a few years back, similar to this model Open Country® Electric Food Slicer | Bass Pro Shops. Its not super high end either, but as infrequently as we use it, I couldn't justify spending more. Two big hassles, the feet don't stick to the counter so it slides unless I prop something behind it, and two, it doesn't have a high power motor so can bog down a bit. But we can use it on blocks of cheese from the warehouse store, making jerky (partially freeze the meat first), and I occasionally smoke some wild game that I slice for lunch roll ups.
I do think the meat slicer is really nice for making jerky, but I wonder if the clean up time of the slicer is probably about the same as the time it would take to cut it by hand . On the flip side, homemade jerky is best when you can get the width consistent, which is sometimes hard to do by hand depending on your cut of meat.
If I lived in a smaller space like an apartment, I don't think I could justify storing those two large accessories. I would probably just use the oven method and cut the jerky by hand.