As a beginner, I asked myself the same question not that long ago. Infact, I did a little calculation on it the other day and came up with the following.

For a couple a 2nd hand razors (two of which were sent off for honing),
A norton 4000/8000 combo hone,
A good strop from Tony (I haven't actually bought yet but I'm going to soon
A kent Pure Badger brush

It cost me about £80-£100.

Now, using this same amount to buy a Mach 3 Blades (which would cost me about £1.50 per head [which is the same price I paid for a good usable straight on ebay ) ]), ashuming that I could use each head for about 2 week of everyday shaving (like that's going to happen beause they never last me that long), I would only be able to shave for just under 3 years.

Now, I belive that the razors, the stone, the strop, should last me for a very long time (maybe even for ever ). So after that calculation I realised that it is actually cheaper to use a straight (with all the extras), as it should pay for itself within about 3 years.

Well there's my thoughts anyways.

Steven