I've done a rough estimate in my head before...
Canon XSi w/ beginner kit- $780
18-200mm lens - $600 (gift)
100mm macro lens- $500 (gift)
Sigma 30mm f/1.4- $326
Gorillapod - $30
Tripod- $10 (it's a baby one)
camera bag- $40
another camera bag- $50
memory cards- $30 I think?
580EX II flash- $420
flash cord - $70
remote cable- $30
Photography classes (2 semesters) - $600
Supplies for class - $100
Smugmug acct- $20
So that's about $3600 worth of stuff, $2500 of which I've actually spent.
And I've got plans to buy (before our trip in September):
Crumpler 5MDH ($80)
Polarizing filter & 72-77 converter ($200)
Memory cards (2 x 4GB) - ($20-$30)
Oh and the 24-105mm f/4.0L within the next year... that'd be another $1200
This is over what's been almost a year. I bought my camera in late August of 2008.
It's a hobby! Things could be worse. I know people who are into hunting and fishing that also spend thousands... I just keep telling myself that this stuff will last a long time and can be used all year round. Now if only I could just stop myself from wanting something else everytime I buy something!