I have made hundreds of great transactions on Ebay, a excellent place to get hard to find items!!
But Ebay prohibits a seller, selling outside of Ebay! Because for every sale Ebay gets a little precentage.
Anyway I purchase everything with a money order.
The seller doesn't have to wait for a check to clear, your not giving credit card info over the web (even though they say it is secure, better not to just too be safe) and if you don't get your item you can track the money order! and get your money back.
As far as feedback, I usually go by the positive, I have found a number of times that the negitive feedback was put by somene who didn't realize what they were buying, and if you look into some of the ones leaving that bad feedback, they leave it to everyone they buy from. I have also bought from people with no feedback, with good results.
Ebay does a good job against people who are fraudulent but the risk is there.
Now what you need to do is take the price you can get the item for, then add the S&H too see if your getting a deal! Often times you can buy it locally cheaper. Check into the cost of shipping that same item to and from place if purchase, to see if you are being charged a fair price (many sellers will tack on a outrageous S&H fee too make profit!! ex. 1 cd= $8 s&h, when it is really only about $1.50 to mail one) and if they are ofering insurance for a buck or two get it! if they aren't ask for it, there are some that won't offer it, then when your package dosent show up and you ask them where it is, they'll tell you it was mailed and must have got lost, all in all it comes too "Buyer Beware"!!
I have been pleased with all my transactions so you might too, and also beware Ebay is adictive!

Good Luck!