Do it yourself.
My homemade tower is from 3" wide strips of bass wood obtained at the local Hobby Lobby. Grab some 1 foot squares of thin corkboard to line the tower and you can put one together in a few hours with an x-acto knife and wood glue. You will also want to pickup a 3/4" or 1" strip of bass wood as well for the walls of the tray (or be willing to cut along the grain on the wider strips). It will take approximately 42" of the 3" wide, about a foot of the 3/4" or 1" strip, and two patches of cork at 3x7 and 3x6.
The primary dimensions were selected so I would have to make as few cuts as possible. The main tower is therefore 3" x 3-1/4". I determined the height by laying out baffles at 45 degree angles and guessing how many and what size they would be to have 4 of them total, without making the whole thing too tall. Remember that the bottom one has to roll the dice out to the tray, so work up from the bottom. Clearance between baffles depends on the dice size used. I got some larger dice recently, only to find that they can get stuck in the tower on occasion...
It's about 7" high, each baffle is about 2" long, the total length is also 7" or thereabouts, so the tray has about 4" of "run" for the dice. Cork is lining the front and back of the tower, I should probably add some to the tray and the baffles to lessen the noise a bit more... Quieter than a glass, but noisier than one of the finely crafted "Cadillac" models.
Fanciest thing I did was bevel the edges of the baffles with a Dremel before assembly. Make sure to put the baffles in when one side is still off the tower. Hold everything together with rubber bands overnight till the glue is good and dried...
If I was going to make another one, I wouldn't use quite so much material on the "front" of the tower. The baffle just above the tray leaves a void of sorts between it and the front piece. So if a die stops short "inside" the tower it's not readily visible. I would also go with the 3/4" high walls on the tray. When using the standard ASL dice, sometimes pips are hidden behind the tray wall at some viewing angles.