[themike537]

Potential buyers would want to see:

proof of income - screenshots of paypal or however you're receiving payments

traffic stats - more than your # of visitors, you'd want to include your traffic sources, which keywords you're getting hits from, what pages are receiving traffic, etc

I agree with Jeremy that Alexa isn't really important, but I'd estimate the site at more like 1 year's revenue, so probably $10-$15k (depends what your revenue was in between March and now)