To make things as confusing as possible, i might add...I don't very much like the lunas i've played, lots of intonation problems, Kala is a very solid brand, but my favorite for the 100 dollar range is hands down the lanikai spruce tops... Spruce is a delightful wood for ukes, and tends to be loud and proud. BUT all this said...it comes down to personal preferences. The biggest thing to keep in mind, is that ukes in the $100 price range tend to very WILDLY from instrument to instrument, same make and model. They just don't take their time and you get what you pay for. So sometimes it works out perfectly, and you've got a uke worth lots more than $100, but often times it just didn't go together properly. I think 100 is a perfect price to start at, but playing the uke first OR buying from someone who "sets up" the uke, like Mim @ mimsukes.com can really make a difference. A good seller will check for things like tuning, and action (how high strings are above the frets) and any major screw ups. If you want to check well for yourself at a music store or the like. As to borrow a tuner, or have them help you. When you pluck one string at a time and put your fingers on the frets moving up the neck, you really shouldn't see too much variance...maybe 5 cents or so ( you'll see that on the tuner readout). I find this is one of the best indications you've got a well put together uke. If the strings are two high, or the bridge put in the wrong spot, you'll see variation in the tuning, which means even when the uke is completely in tune with the strings open, you'll be out of tune when you play a chord...something that can't really ever be fixed (easily). this intonation problem is pretty common in ukes less than $300 (and even some for more) and can be avoided by shopping around, or buying from a trusted seller. As far as the aquila strings....i personally feel you can't go wrong! i have 15 ukes and just about 15 sets of aquilas...they are loud, warm, and full...and have a reputation of making a inexpensive uke sound like a million bucks. Have fun with your new uke!
Alex