I tried to buy the standalone ‘Entourage’ version on the say intentions website today and kept on being directed to the subscription service.
After raising a ticket with SI support I was told that they had stopped selling this as a one-off purchase.
I notice, however, that it is still showing as being available to purchase on their own website, on Contrail and, I think also, on Simmarket.
Not sure why it is still showing as being available for purchase on all these websites when Support said it was no longer available as a one-off purchase.
Very very strange 
Edit: I have contacted support again for further clarification since their initial response didn’t sit right with me. In their second response they apologised for initially incorrectly saying that the package was no longer available as a one off purchase. In their second response they have said that ‘Entourage’ still remains available to buy as a one-off purchase.