Blickensderfer ‘Model 8’ typewriter, circa 1908. Seen at a silent auction; no idea how much it went for, but the current market value is $400. Info from Wikipedia:
Instead of the common mechanism with letters on the end of individual bars connected to the keys, the Blickensderfer used a cylindrical wheel with letters embossed on it. Pressing a key caused the cylinder to turn so the correct letter was positioned over the paper, and continuing caused it to be inked by a roller as it moved to press down on the paper. The mechanism is very similar to the IBM Selectric design introduced decades later, with the only major change being the shape of the striker. Like the Selectric, one could easily change the typeface on a Blickensderfer simply by changing the type cylinder.
The Blickensderfer 8 of 1908 was the first Blick to boast a tabulator system, even though tabulators had been around for some time. The tabulator used large nickel-plated levers placed on top of the machine, making it easy to operate. The typewheel head had also been altered, and was now made from two castings instead of one, which allowed easier access for repair and adjusting of the mechanism.