Where and how does one dispose of expensive sex toys?
Check first what materials they are made of. Glass, metal and wood toys (without motors) can be recycled just as you would any other item of the same material (ie. go ahead and take your glass dildos to the bottle bank).
However, the majority of modern sex toys are silicone and motorised. If they're electronic toys, check the brand. Companies that supply electronics have an obligation to help you safely dispose of their products and should have a system in place.
Usually the process is that you remove and recycle the batteries yourself, and then send the toys off to a given address. So get in touch with the companies, and if they're reputable they should help you out.