Regardless of anything, the tonal difference between ivory and good bone is gonna be pretty minimal, and no matter what anyone tries to tell you, the continued sale and use of ivory from any source only leads to increased demand and poaching of elephants just for their ivory. Just like illegal drug sales and distibution has severely negative effects in the neighborhoods it happens in, this poaching is being done by gangs and armed militant groups that also threaten the lives and safety of villages and local residents. And on top of that, anything with ivory can be impossible to travel with (and can possibly get seized at borders).
Its everyones choice, but before considering ivory, exhaust options with strings, picks, and really good bone saddle and nut (which you would already have on a SCGC instrument) and set-up. Scarcity and cost might be appealing for some, but the secondary costs of ivory are too great for me –