Derby Extra blades are not the cheapest, but they work great in my estimation. I just checked, you can get a thousand blades for $80. I easily get four or five shaves out of a blade, so that pretty much gets me through a week. A thousand weeks is 19 years worth of shaves. I tried the really cheap ones from CVS... oh hell no. I'd rather shave by ripping a Coke can open and scraping my neck with that.
Feathers are the Japanese blades that are amazingly wicked sharp. Feathers are $32 for 100, so $320 for a thousand, which will last you 19 years or more, because I've heard Feathers will give you more than five shaves. Maybe six or seven? Dunno, I haven't used them.
Some say that beard prep is the most important variable in getting your DE shave on. I agree. Hell, once I learned something about beard prep I don't even need to use a DE anymore. Any cheap disposable razor does a great job when you take a long hot shower and make sure to work that hot water into your beard for a good couple of minutes right before you get out and shave immediately after.
Some of the guys on badgerandblade.com and shavemyface.com spend 45 minutes shaving in the morning. Not me. It's a two minute thing at most.
Then again, I drink Trader Joe's wine, smoke $3 cigars, load up on London Broil when it's on sale for $2 a pound, drive a $3,000 4x4, etc. My favorite pocket knife is a Kershaw Leek. There's much better stuff out there, but baby needs a new pair of shoes.
I do very much enjoy shaving with a DE, though. It's a nice traditional thing to do. I never thought the cartridge systems were all that great anyway.
Also, check out the Schick injectors. The razors kind of look like the cartridge system razors, but they use a single one sided blade. The Schick brand blade injectors with seven blades are about five bucks. But... one time I found a link to a medical supply house that essentially copied the Schick blade and sold them as a specimen slicer or something like that. They came in a 400 pack, I can't remember how much they were but holy CRAP was it cheap. Even the cheap CVS blades made that thing hum. I got a better shave out of the Schick injector than I've ever gotten out of a DE.
www.badgerandblade.com
www.shavemyface.com
Both of those places are great resources. Even if they are a little Metro.