Not sure "afford" is the question. Value for the price of their GPS, to use the already paid for proprietary mount and "magic" wheel, is the crux.
I totally agree. I can afford anything. I don't like to be taken for a ride.
Years ago, Garmin made the Zumo 550 and Nuvi 550. Specs were virtually identical. The Zumo was obviously the "motorcycle" version and the Nuvi the lower class "car" only version. Both were waterpoof. Both had 8 hour battery life. I wouldn't be surprised if the innards were identical.
There was a huge price difference between them. I don't remember how much, but I don't think I'd be wrong to say the Zumo was three times the price of the Nuvi...and none of them were that cheap in those days. Some riders got smart and realized the only difference was the shape of the case and the price. They bought the Nuvi up in droves. Garmin got smart eventually and stopped production of the Nuvi. Since then, they've maintained a difference between their "car" GPSs and their "motorcycle" GPSs.
I mitigated part of the price of a new "motorcycle" GPS by purchasing a refurbished unit. Looks like new. Full warranty. And hundreds less than the new model. And I know they are still making a profit.
Chris