We were advised by the park guide that this was a strenuous climb (800 steps) and that you shouldn't take a donkey up as this was quite dangerous.
We set off in the nearly morning (8am) to avoid the heat of hthe day - highly recommended in June! While you definitely need to be fit to make this climb it is not as arduous as they make out, especially if you take your time.
Takes 1hr to climb up, 30-40 min return. Gift shop and drinks at the top. You can easily spend another hour walking around the top.
IMO you cold take a donkey up the stairs as, unlike the Place of High Sacrifice which is quite steep, most of e route has a gentle slope. So if you're unfit take a donkey for 5JOD. I'd walk down though!
On the way up and down there are plenty of places to buy souvenirs and the traders are not too pushy and are very friendly.