On Wednesday, September 27, 2017 at 9:29:12 PM UTC-4, wrote:

I cannot justify spending 3-4 thousand dollars on my $12,000 Libelle.

I have Trig TT21 in a nice 18 year old medium performance glider. Here's how I justify the cost.

The utility/value of a $2000 transponder is the same whether it is installed in a glider worth $10,000 or $100,000. Amortized over 10 years, it costs me ~$200 a year, a small fraction of what I spend on flying each year. Cost of a mid-air collision is priceless.

If the eventual buyer of my used glider does not want to pay the depreciated value of my transponder, I could pull it out, sell it used, put it in my new ship or put it in a club glider. Or maybe I'll just kiss it goodbye and feel good that the new owner is flying with a transponder.