The price for additional websites depends on how many you wish to add and the payment frequency.
For example if you purchase a pack for 50 additional websites and paid monthly at £19.95 it works out at 40 pence for each website.
If you wish to add just a single website additional website the current prices is £1.95 per month, or £7.95 a year if paid annually.
If you are wanting to add a number of websites you may find that our reseller packages are better for your needs as they allow you to host larger number of websites under the single package;
https://www.webwiz.net/web-hosting-resellers/windows-reseller-hosting.htm