Valuations for ebusinesses

I am considering the purchase of an ebusiness through a website broker. The business has grown to 100K in profit for the owner (one man operation), with 300K in sales aftrer 2 years of operation. The model is basically a drop-ship store, with only 15% inventory being kept and shipped by the seller. Since the only asset the business has is his domain name, website, and accounts receivable (and the marginal 15% inventory he keeps on hand), what is an appropriate way to value the business? I know that 3x's net profit can be a favorable valuation for a B&M business from the buyer's perspective, but does the same hold true for an e-store?