A very nicely made traditional folder is the Kershaw 1993-2 'Gentleman's Folder. It has a 3.1" lockback blade of VG10 steel, with a finely made black Micarta handle with brass rivets & lanyard tube. It comes with a vertical leather sheath that clips on your belt - no clip on the knife. It is a beauty - and sturdily built (Made in Seki, Japan for Kershaw.). I am a US-made knife junkie, but this one is nice! It's MSRP is $120 - b&m store mail order ~$70. I bought mine off evil-bay for $60 less a 10% discount a few weeks back - a bargain, even if slightly over your budget.
Another bargain, although likely $50-$60 plus now even mail order, is the Spyderco S30V Native. Mine was <$40 at wally-world, but they parted ways last summer. Not before my wife found me a 'spare', thank goodness. It is super - very stable locked and just difficult enough to open to make accidental opening a near impossibility. Great ergonomics, too. It has a reversible clip, too. That S30V stays razor sharp, like it came, for a long time. My first one was nearly 15 months old when I elected to resharpen it with my Spydie Sharpmaker. While taking longer than my Buck 420HC blades to resharpen, it wasn't the new career that my BM's 440C or D2 blades were. Made in the USA, too.
Of course, if they liked the Buck Prince, there is always the classic - the big brother - the Buck 110. They are work horses, but no clip and the blade is 3.75" - they are a pocketful. They are a real bargain, too - actually a few cents less than the Prince at Wally World ($25), despite being US-made.
Stainz
And under $50....Shipped