For a first EDC, you have a lot of options at this price. Just about every major production knife company has several (sometimes dozen) knives at or below the century mark. Spyderco, Kershaw, Benchmade, and CRKT all come to mind.
Personally, my first "quality" EDC was a BM 556 Mini-Grip in 154CM, and I can't recommend it enough. If you look around a bit you can get a plain-Jane model (black handles, plain satin finish blade) for ~$60, or upgrade to S30V or an RSK model for a bit more. If it's too small you can also go for a full-size Grip, I'm not sure of your preferences. The 154CM is a great starter steel because it'll take a fine edge and keep it while still being almost as easy as 440C to sharpen (Out of the box, with modest daily use and some intermittent whittling of a half-dozen cedar deadfalls, my first Mini-Grip was still sharp enough to give me five stitches without my knowing it until my pants leg started to turn red, so be careful!). If you go for a higher-end steel like s30v or D2 (about the best you'll see at this price), you'll notice a bit of a gap in the difficulty of sharpening. One of the best features of BM knives is the Axis lock, it's fast, easy, solid (no hiccups in mine over the past 6 or so years), and even fun. If you've never tried it, please do before you decide on a knife. I would also recommend the mini or full-size Barrage, a very similar model.
My second recommendation would be the RAT-1 from Ontario, especially if money is a big concern. At $40 MSRP, it's a great, solid knife that nearly anyone here will tell you is one of the highest value folders out there, and would be a fantastic starter knife.
I'm not a huge fan of Spyderco knives, and they don't have the thumbstuds you wanted, but if you like the looks of them they offer some great options from EDC in s30v and sometimes even better steels around that price point.
Kershaw has some enlightened designs, people either love them or hate them. Try them out first is my advice, if possible. Both the Cryo or the Skyline are good choices, the Blur is a very well-respected design that has received much love from all over.
I've never personally had any CRKT knives, but I hear pretty good reports on them, some research would be healthy there.