I'd say, more than you own skills, it depends on how the endorser wants you to do things.
They could sign you off in a few hours. Or 20 hours.
I think it depends on planes, and the trainer's standards.
I was flying everything pretty much around the 4 or 5 hour range to about as good as I do now. But, the place I train likes to hit wheel landings real well (which is fine with me, since they are fun
) and make sure you have some real x-wind practice as well. In addition, I was doing the work in two similar but different planes. A 1946 Aeronca Champ for a lot of it, and a 60s era Citabria for most of the other time. The school has a checkout requirement before you solo in their planes, which includes flying with the owner/cheif pilot (who is the son of a fairly famous aviator in these parts who passed on a few years ago). I did their required 3 supervised solos, couple in the Champ, one in the Citabria, then I was on my own. The first of those solos obviously came after the endorsement, and think it was around 12 or 13hrs. I think the place I went goes further than most that would just sign you off. They want you to be safe. Going through landings where they mess things up on purpose (you know, passenger in the back kicks the rudder as you are about to land) to see how you handle it. They also ask for a couple hours solo before you start taking passengers in their planes. They are a tailwheel only school, with the 172 they have going about 10hrs or so a month (while most of the tailwheel planes do that in a week, easy).
www.ameliareid.com
Landing in a lot of wind isn't hard. The taxi of the runway is
Anyhow, getting the endorsement, and knowing the plane enough so you won't hurt yourself are two different things. The first, maybe 6 hours. The latter, at least twice that, and always flying 'em to keep current.