Yeah I go to have mines done at the hospital the end of this month with my insurance so you shouldn't have to pay unless you really want it done right away.
If you already have insurance and seeing your obgyn, he/she may offer that to you around 27-30weeks as a gift to you. I would just ask your obgyn if its offered. I just had my 3D done yesterday , i receved pictures and a home dvd, its just asking for it is all.
I'm not sure the prices where you are at but most places start off at $99 n up but look on line for 3D ultrasounds in your area..