Hello Dirke,
I make my living making chocolate confections and I will tell you that my confectionery guitar is one of my most important pieces of equipment. They are pricey pieces of equipment, but ultimately this tool helps me save money and make money. Several years ago when I was cutting with a knife, I would end up throwing a good amount of chocolate away because the resulting ganache was either too big or too small or funny shaped. Prior to chocolate I spent 10 years cooking in fine dining. I have excellent knife skills; however, cutting ganache is tricky and sticky and it is very hard to cut thousands of pieces into perfect squares. These days, I have very little waste and the guitar helps me produce more chocolate confections in a much shorter amount of time.
If you are looking for a confectionery guitar, I highly recommend the dedy brand from Germany. TCF sales in Texas is a great resource for these. Tom Polk who runs the company is a great guy. I have the base and just 1 frame. It cost me around $2,000 . I am not a fan of the cheaper guitars with a plastic base. They are very hard to clean and the frames that accompany them have a very cheap handle. The Dedy handle makes cutting much better and allows you to distribute your weight on the handle more evenly. The base of the Dedy is metal and it is so much easier to clean. It might be a few hundred more, but you will be glad you spent the extra money. I typically don't see a whole lot of used guitars. I would never sell mine. Whether you buy a used or new guitar, you will be very glad you made the investment! Good luck!!!