Koss TD80s I believe are no longer made but a few dealers may still have them? Yes, they can be a pain but a new set of ear foam for them is about $10 and these should last one detecting year (depending on how often you go out). If you have TD80s I would suggest you get some spare foam while they are still available (peel and stick). They get a tick from me, robust, good strong manufacture.
the Koss UR 30 - take headphones, place in hands, drop on foot at the correct angle, kick them straight into the bin. very comfy, very badly made for the bush. Great for listening to Jim Reeves, Slim Dusty and Hank Williams records and that, in my opinion, is about their limit. These were the old standard Minelab issue with new detectors - I've had several pairs and they literally fall apart. Minelab should have been held to account over issuing these pieces of cxap. Good for limited use. Am I pissed over these? You betcha - let down many times.
My next set will probably be the Nugget Buster/Grey Ghost.