How to handle inventory in an e-commerce business acquisition

I'm targeting an e-commerce business with ~$6M revenue. Seller is currently both a wholesaler/distributor of a brand name product and he has a retail e-commerce site that sells the brand directly to consumers. These two components (wholesale and retail) have been operated as one business but he's selling the e-commerce site and holding onto the wholesale/distributor side. One of the challenges is that the seller didn't keep separate books for the retail e-commerce site. Revenue and most expenses were easy to break out, but the balance sheet was not. Determining net working capital will likely be a bit of a challenge and I'm not sure how I should propose to handle inventory. The seller indicates that he doesn't intend to include any inventory in the purchase price, which I understand is fairly common in the acquisition of a retail business acquisition but without a balance sheet to help calculate NWC, I am not sure if I should ask for a "normal" level of inventory to be included in the purchase price. Any thoughts on how to handle inventory in a situation like this? Thanks in advance.