RevDave -- I suggest investing $50 or so in a carboard dulcimer. The sound is good, the frets are dead on and intonation can be adjusted if needs be. They're a greater learner instrument, and can be 'upograded' by making a simple wooden box... The picture shows a cardboard dulcimer fretboard transferred to a Virginia-style elliptical body that a student made ...
cardboard? Really! These things exist? I once made a nominally working “organ pipe” from a sheet of notebook paper, but a cardboard dulcimer…
I assume made from corrugated boxlike material? How do they hold up?
It's often thick sheets of really stiff paperboard, but some are actual corrugated cardboard. Because the board is very stiff and lightweight, the instruments are shockingly loud and punchy, especially for their price. The box itself will not be durable if you're not careful, but the fingerboard will be good quality, and as Ken mentioned you can simply remove the fingerboard and glue it onto a different box later.
I've seen them in kits that you assemble yourself for as little as 45$, but for under 100, you can find some that look and sound pretty nice.