Hi, I've been helping people sell businesses since 2009 and recently wrote the best-selling book 'How to Sell My Own Business.'- Available on Amazon or at www.HowToSellMyOwnBusiness.com
There are many firms and professionals who could do a valuation on a pre-revenue business. You would need forecasts showing what the likely sales, costs and revenues would be in the future.
Getting a potential buyer to agree with the assumptions and pay you for sales and a cash flow that doesn't exist is another matter.
Typically business buyers are looking to acquire cash flow or buy something that will make their own company perform better.
So if your startup has a spectacular new technology that will help company X to save costs or make more sales of their own, then they'll see value in buying you.
The trouble is identifying these synergistic buyers and getting them to pay you for advantages that they will have to achieve post-acquisition.
If you'd like to chat, arrange a call.
Thanks
David C Barnett