[silencio]

The counterexample needs a huge caveat. Outside of one-off registry discounts and occasional manufacturer end-of year/model/design sales, the Target trade-in deal is one of the best deals you can get on baby/child gear. Parents in my local groups will hold on to seats from accidents and more, just to get or give away these 20% coupons.

[bluGill]

I suspect most second hand car seats are immediately traded in. If you watch the market most second hard car seats are sold at the time of the target sale.