I own the copyright of a magazine and a weakly .
I want to sell this stuff to somebody who is interested .if i find a potential buy , how we are going to decide the price of my copyrights , can i legally sell my copyright at a $$$ bigger Price$$$
i know one Yahoo wanted to buy facebook for +$1
The potential value of your copyrights is probably fairly close to zero. You have already published things, so copies are already out there for the public to read and discard/sell. If you were to find anyone infringing your copyrights, that might be worth something, as you could (in theory) sue them for damages. There are actually companies that buy rights from others to sue infringers, but it’s a narrow niche.
Your trademark, on the other hand, may be quite valuable within your market and there are literally volumes of business and legal books that discuss the mechanism for proper appraisal of trademarks and their associated good will.
If you own the copyright, you can sell those rights to anyone you want for any price you want. Of course, the buyer has to agree to the price. You can’t force them to buy at an inflated price. But if they are willing, then go for it.