Well, unlike in the good ole days, now you can get a monster Dob with good optics for under a grand! .. and a fantastic starter Dob for a few $100.. and very capable eyepieces for a few $10. So it's not all bad!
But I'd say you'd be lucky to get a lenscap for $5 let alone a useful camera accessory. Sorry, there is no mass market for M42 adapters.