Small, GPS type antennas cost just $675 for an installation drawing & 8110-3 approving the drawing for your aircraft with a one (1) business day turnaround time.
Larger blade antennas cost just $1,050 and turnaround time is a few days if we have not designed an installation for it already.
These aircraft require a damage tolerance evaluation (DTE), which drives the cost up to $3,000. This cost includes a drawing, DTE report, and 8110-3 approving both.