The price of Yashica-Mats has gotten rather ridiculous at times in the past too, with 124G's sometimes selling for more on ebay than a good user Rolleiflex with a Tessar lens. I checked ebay today and found eight 124G's that sold for prices ranging from $375.00 to $499.00 The Yashica lenses can be pretty good, but the build quality of the camera is nowhere near the same quality as the Rollei.
When I bought my 1954 Rolleiflex MX-EVS, I was actually looking to replace my much loved Yashica-Mat EM which had been stolen a couple of weeks before. I went into the old Linda Mar Camera shop in Pacifica, CA to see if a suitable replacement was available. They had two TLR's in the used equipment case. One was a fairly new Yashica-Mat 124G and the Rollei. I remember that the price difference was probably about $30.00 US. After comparing the two cameras side by side, I KNEW that the Rollei was the one to buy.
I only wish that the instruction manual was included in the sale, as I didn't know how to load the film properly and I made the classic mistake of not threading the roll through the rollers. After winding the roll through the camera without stopping or engaging the frame counter, I thought the camera was no good. I made a frantic call to the store and the owner said "Oh crap, I forgot to show you how to load it. I forgot that your last camera was a Yashica. Come on back and I'll show how it works." When I returned to the store, he asked me what film I loaded into the camera, grabbed a roll of the same, and demonstrated how to load it properly. He then gave me two more rolls for my trouble and apologized. My first shots showed me why these cameras are so highly regarded. You definitely get what you pay for, although a new Rolleiflex is way out of my reach financially.
The old girl's shutter is getting kinda sluggish, so I'm going to have her Fleenorized in time for her 60th birthday.