Well I'm not sure you will be getting away with much cheaper because of firing costs, cost of kiln, and such. The other thing to consider is ceramic is one heck of a lot heavier than any wood I've encountered, so you will be adding a fair amount of mass. If you are looking for performance, I'd be leery. If you just want aesthetics on the other hand, I'd say go for it , the sky is the limit. You might consider sculpting what you want out of clay, making a silicon mold, and then casting the piece out of resin. That will still add some weight depending on what you want, but it will be much better than essentially gluing rocks to you bow tips. What temp are you planing to fire to? The higher the better would be my guess. I'd fire as high as your kiln can take (with the appropriate clay). I would go to cone 10 as a minimum, but more than likely your kiln will not go past that assuming it is an electric kiln, it may not even go that high. Personally I'd go to cone 12/13 in a gas or wood kiln and then salt it (less glaze weight). The minimum I would fire to would be cone 02, below that and you can snap most things with your hands. Even cone 02 might be to low depending on the clay body. Try and come down through quartz inversion as slow as possible for this project. Ceramic material is great for wear resistance, and does okay in compression. It does not do well flexing or with physical shock at all, unless you get into some of the "super" ceramics such as knife blade material, Corning Ware, engine cylinder sleeves, etc. Unfortunately those are likely beyond you and I, especially since the manufactures are not likely to share their clay formulas. I'd say that a COMPLETELY non-bending tip section is mandatory depending on nock/overlay design, and be real careful about banging the tips around once mounted on the bow. Let us know how it turns out.
Swamp