Is the Furniture Worth Reupholstering - the Foundation?

Thanks to an elderly furniture salesman that I met while trying to help my daughter with her first sofa purchase, I found the value of 8-way hand-tied coil springs.   He told us that only the very best furniture makers use them and that they were REALLY important in determining the long-time comfort and durability of upholstered pieces.  You can easily tell (I can do it in less that 5 seconds) whether the springs exist or not - just feel UNDER the piece not just under the chair/sofa cushion - for the large round coils - sometimes held in place by a latticed metal network.  When I buy pieces and consider whether they are worth making the large investment in fabric and upholstery labor, I always check for these coils.  If they are there, it's worth redoing the piece - if not, check for other signs of "worthiness" but, generally, it's not worth the expense!