I have a little more work to do on the stand, the 'side boards' that set the play height and position they keys are pine, I'll refashion those out of the same wood as the keys, right now they are the pale looking pine. That should be over the next couple of weeks, for now it's near the piano and ready to play.
I used Brazilian Walnut (Ipe) flooring that I got off a clearance sale for the keys and frame. It was ¾" thick and really dense and hard. That was about $100, I had to buy twice as much as I needed because it was a close out. I have enough for keys for another small project. Flooring supply places might be a good tip, in the US we have Lumber Liquidators.
The legs for the frame were purchased off a kitchen supply place, I had to cut them a little with a plasma torch to get their pedestals to the right dimensions. This was by far the most expensive part $250, but it saved a lot of time and efforts. With the upper and lower cross braces it is super solid, and I was looking for that. I looked for legs in trash piles here and there, but never found anything good, I really like the ones that I bought.
I figure that I have about another $125 or so in hardware, I used 1.5" long 10-24 thumb screws that I slotted on a milling machine for the bar posts. They gave me more height and an adjustment for height. They fit nicely in the 1cm between the keys. My key height was really good so I didn't bother with the felt, and that isn't causing any problems even when you haul off an really hit a key.
Fortunately my resonators were made from scrap aluminum for free. I bought PVC rod and cut it into disks, then sanded those until they fit inside the tubing for the stops.
Maybe I had another $100 in tools, but I'll have those for the next time.
So even with the tools it's about $550, plus time. I built it over weekends at my at my home between 4/10/11 and 5/22. Maybe I have another 6 hours to go on the side boards.
It was a cool project, I enjoyed it. The first time that you make a resonator work the right way with a key is a real thrill. My daughters piano / marimba teacher is amazed, especially because its tuned to A-440, and pretty much its right there all the way up and down. The marimba sounds good when played with piano or acoustic guitar accompaniment, really happy with the tuning. Some second harmonics are right on the money, some are not, but I like it. My C#3 is a bit of a dud, but its right on the end so I may yank it off and sand some more.
Thanks again, it was a fun project and sounds good,