It depends where and what you're buying or selling. I've just bought a job lot of mixed photo junk and it's worth a lot more than I spent. Most items need cleaning up or repairing. I took a risk because two items couldn't be seen clearly but.
Originally Posted by Two23
I had my Rolleiflex 3.5E valued by Rollei 15 years ago at £750, that value dropped but I was told by a camera seller at an antiques market he'd pay £500 and sell it for £750, he knew I wasn't looking to sell it though. The camera cost me very little and I no longer use it much because it is partly an investment they won't drop in value again.