+1 to groupon. I also recommend checking out the classifieds section here as well as homebrewfinds.com.
The Better Bottles are great as long you care for them properly. I do an oxiclean soak in warm water, rinse as needed. Do not scrub them.
Links are example only, not a specific vendor recommendation. You can't go wrong with Morebeer, Austin Homebrew or Northern Brewer. Recommended item list based on your requirements:
8-10 Gallon boil kettle: (I would recommend considering your options. I've upgraded my pots 3 times in the last 4-5 years. If you're doing 5 gallon batches, you'll want a 8-10 gallon pot. Stainless steel and aluminum are both acceptable)
http://www.amazon.com/gp/product/B0...=1789&creative=390957&creativeASIN=B001CHKL68
http://www.northernbrewer.com/shop/brewing/brewing-equipment/tall-boy-kettles.html
http://www.austinhomebrew.com/product_info.php?cPath=178_33_463&products_id=10460
http://www.northernbrewer.com/shop/brewing/brewing-equipment/tall-boy-kettles.html
Fermentor: (I would recommend starting with a bucket. They are cheap, durable and easy to replace after a year or two)
http://www.austinhomebrew.com/product_info.php?cPath=178_33_464&products_id=10774
http://www.northernbrewer.com/shop/...g-equipment/6-5-gallon-fermenting-bucket.html
http://morebeer.com/products/speidel-plastic-fermenter-30l-79-gal.html
Bottling bucket: (you don't need a separate bucket if your fermentor has a spigot, but I would recommend spending the few extra dollars. This will reduce the trub transfer)
http://www.northernbrewer.com/shop/...ing-equipment/6-5-gallon-bottling-bucket.html
http://morebeer.com/ct/?idx=921134&i=16591&u=/products/plastic-bucket-spigot-6-gallon.html
Bottle capper:
http://www.northernbrewer.com/shop/red-baron-emily-capper.html
Bottle caps:
http://www.austinhomebrew.com/product_info.php?products_id=982
Auto Siphon:
http://www.northernbrewer.com/shop/auto-siphon-1-2.html
Sanitizer: (you'll need a sanitizer, I personally use Star San exclusively)
http://www.austinhomebrew.com/product_info.php?products_id=513
Cleaner: Oxiclean FTW! Get the generic brand. Make sure it's chlorine free, non-scented.
Burner: Get a turkey frier at harbor freight or amazon.
Bottles: You can use any non-twist off bottle. Drink and save
Just make sure you rinse them as soon as you finish a beer to make cleaning easy.
Hydrometer, refractometer, ph test strips, etc: Not needed for extract brewing. Extract yields 100% as listed on the kit. The only benefit is if you plan on using it to take readings at the end of fermentation.
O2 system: Not needed, nice to have. I shook the bucket for quite a while before I picked one up.
Beer making ingredients: Now you're getting to business. Shop around and pick a kit that sounds good.
If you haven't already, I recommend picking up a copy of 'How to Brew' by John Palmer. Good luck and happy brewing!