The Canon 75-300 III is not known for high quality. It's a cheap starter zoom that will allow you to play with a large zoom range. I had it at one point, but I quickly sold it for the Sigma 70-200mm f/2.8 because the Canon was 1) slow to focus, 2) soft throughout the zoom range, 3) obnoxious when zooming in/out because the front element will extend out.
Instead of the 70-300, try looking into the Canon EF-S 55-250 IS
lens. Although it still has the extending barrel, you get the added benefit of IS and sharper optics, so more of your pictures will come out in focus and sharp.
UV filters will generally not be necessary unless you are shooting in harsh conditions where junk will be flying onto your lens. For example, at the beach, there will be sand blowing around, so having a UV filter may help prevent pitting and scratches on the lens' front element.
Extra batteries can be had for cheap from SterlingTek
If you've got a camera store local to you, check it out and see if they have any sales on camera bags and tripods. If they don't, just go anyways to see if they have any nice bags or tripods that you would want to buy, then check the price online at places like Adorama.com or BHPhotoVideo.com.
Same thing with SD cards. You can find them super cheap online compared to at a place like Ritz or Best Buy. Just remember to purchase everything from a reputable shop online. Not eBay. eBay is known for sellers with fake/stolen/grey market goods.
To break down the extra "accessories" found on that eBay auction:
"Wide Angle Lens" and "2X Telephoto Lens" is an attachment that you screw to the front of your existing lens. These generally degrade image quality and you don't get a noticeably wider image. You'd be better off without one.
3 piece filter kit will generally be unnecessary. It will come with a circular polarizer, a fluorescent light filter, and another one that I can't remember. You will never use the last 2, but the polarizer might come in handy if you shoot things with lots of reflections (i.e. cars, buildings, windows...).
Hard shell case is not needed, and it's actually fairly easy to break/crack.
Digital flash looks like junk. Wouldn't put it on my camera if it was free.
Remote control you can pick one up for $5 on ebay.
Tutorial DVD might be useful, but you could just as easily watch a few videos on youtube.
Mini travel tripod will not work if you mount that 75-300 lens on the camera.
Lens cap holder? Really?
USB card readers are cheap, but you could just as easily (and FREE) use the supplied USB cable to transfer pictures from your camera to your computer.
LCD screen protectors are debatable, but the consensus here is that you will not need a LCD screen protector for your existing LCD screen protector.
I've never used a "lens cleaner" before. I'm the type of person who just uses his breath and t-shirt to wipe down the front element. It's tough enough for everyday use, so it's tough enough for a t-shirt wipe down.
Memory card wallet is not useful unless you have more than 2 memory cards. Even then, it's generally not needed because memory cards come in their own little plastic containers. Kind of a redundant thing.
Canon "Wide Strap," charger, "start up battery," video cable, USB cable, and software CD comes in the box. These are not an added accessory.
The "start up battery" is the right battery to use. There is nothing that distinguishes a "start up battery" from a "normal" battery. Although, like I said before, SterlingTek has cheap batteries and good quality.
Hope this helps.
