Unless you're going to do something very fancy like embossing or thermography, the key cost is timeframe (labour), quantity, delivery charges, and especially the quality and weight of the card being printed upon. When comparing prices, I'd specify 350gsm as a minimum for a business card.
Phone around for competitive quotes - digital printers and lithographers are all using the same machines, so you're not going to get a substantially different result.
If you're still looking/looking again for business cards and want larger quantities, I have printer that I use for clients of mine who are looking for fast turnaround, (24hrs) high quality/low cost business cards. To give you an off the cuff cost, they do 1000 double sided, 400gsm, matt laminated, business cards for £85.80 (includes VAT and delivery).
Let me know if this is something that you might find useful.