On several occasions where a sprung floor was required, but when funds were inadequate I have done the following. Purchase from Home Depot or other similar store an insulation product made from small bubble wrap with foil adhered to both sides. The product comes in a variety of widths, but I buy the four foot wide version. Cut the material into lengths appropriate for the space. A small amount of tape is used to hold the lower floor from moving while the performance floor is being laid.
Tape seems as per normal installation.
I have done this over marble, concrete and slate floors. It is not perfect nor any real substitute for a suspended floor. But when money is an issue for a short term project it goes a long way towards a solution. It's a great source of information and a fun read. Rather than fill up this already long page, I'll make another page for you to link to.