"Budget is a factor". I just did this for a showcase dance. Do you know how to sew? or have a family member that does. Here's an easy fix to your situation (2) solutions to look at.
Go to your neares fabric store i.e., JoAnne's or other. Buy black lycra for dance/swim (4-way stretch)for the skirt and maybe 1/4 yd red lycra as contrast for belt. Place the strong velco inside the "belt" and rip the skirt off when you need to in your dance - I found that a leg split in the skirt helped enormously to get the skirt off when my partner pulled the fabric belt. Buy enough to make a circle skirt the length that you need for Tango(a skirt that literally looks like a donut when laid out on the floor as two halfs put together) The length will be from your waist to the hem (lycra really doesn't need hemming - just a clean cut - I use rotary blade)Serger/sew contrast lycra abric to the inner circle of your lycra skirt, after sewing the two halfs of your circle skirt together. Place velco inside the belt. Wella! a skirt that covers your other costume. Now, if you don't sew - buy a long practice skirt from a nearby dance vendor or order off the web (cheap skirt), create a leg split in the long skirt, place velco on the inside of the waist band. Two alternatives for you. Note: Before you place your velco as there is a top and bottom to it - figure out which direction your going to pull your skirt off - this determines which overlap your fabric belt will need to be. Have a good time. My studio loved - the big reveal!