The figure to refurbish the Coliseum was grossly inflated to help sell the downtown arena at that time. It could have been done for a third of that if desired.
Did you see the bid proposals? The $55 million figure included renovation of the Coliseum (Britt Brown Arena) and the three (3) Pavilion buildings.
Even at that, they wouldn't have had to address any ADA issues, most likely, except/unless they did decide to spend some money on it.
As part of a settlement of an Americans with Disabilities Act lawsuit, the Sedgwick County Commission was legally bound to improve accesssibility to the building as well as other improvements.