Thank you for your interest in SoftXpand, "The Ultimate Green PC".
SoftXpand is sold through resellers and if you would like to forward your contact details to me I will ask Intalect who are the reseller covering Lincolnshire to contact you with an exact quote.
As a rough guide you should expect to pay around £3900 for an 18 user suite (3 X 6 user). This will include all keyboards, mice, usb hubs and OS licenses. No CALs are required with SoftXpand. Additionally you may require monitors if you do not have these already, and in a primary school I would recommend headphones for each student to reduce excess noise in the classroom.
There are now a number of SoftXpand installations in Lincolnshire schools so there should be a reference site close to you.