I agree with flyinacez on this one. Contact the seller, ask questions as he stated, and use paypal. You can't beat it - fast transfer and it logs all transactions. Furthermore, read the feedback of the seller, it's there for good reason. Don't frown if they have one or two bad ones if they have a lot of sellers.... but use your own judgement.
If the buyers say things like shipping took forever, wrong parts, and so forth it's usually good to avoid them. On the other hand, if the feedback is something like - charged too much for shipping... that's the buyers problem. You are or should be aware of the shipping/handling charges before you agree to buy. If you think it's too high then, forget it. If it's acceptable, then it's all good. Don't assume that because they want 10.00 for shipping, the package will be stamped 10.00.... remember, people have to drive to the shipper, have to get boxes and packaging and all that costs money too.
Buying from Ebay is relatively safe and can be a great experience, but just cover your own ass, do your homework on the idea - like you are doing now. In short; find items, read reviews, contact seller, ask questions, and go from there.