Jabba's hovering sail barges just seem so stupid. Is there any reasonable motivation Jabba might have had for using hovering ships when he could just use sandcrawlers or something, which I assume are less expensive and require less energy and credits to maintain?
Three reasons come to mind:
Imagine you are this warlord on Tatooine. You carry a lot of wealth and want to appear as being so. What better way than to float above that dirty, hot sand in a sail barge? It must be expensive to run, which shows just how important its owner must be!
Related to the first reason, but if you are wealthy and have lots of parties, going up and over sand dunes on crazy angles is going to spill the drinks. The sail barge can hold itself level and keep everyone comfortable.
Lots of people use hovercraft on Tatooine!
Think of Luke's landspeeder in Episode IV. It's much the same thing, but sits lower to the ground and is a lot smaller.
Travel time (thanks @WadCheber!)
Sandcrawlers are these huge, lumbering things that travel at roughly the same speed as a sick bantha. Wouldn't it be better to nip over to the Sarlaac pit, drop in the prisoners and be back to the lair in time for the after party?
Put all of those together and it's a compelling argument over a sand crawler :)
According to the new Star Wars junior novelisation 'Return of the Jedi: Beware the Power of the Dark Side!' Jabba's motivation to get a Sail Barge was a mixture of comfort, convenience and the desire for a display of ostentatious wealth that befitted his reputation as a key mover-and-shaker in the Sector.
JABBA, OF COURSE, has never been satisfied with the various landspeeders and skyhoppers that the common folk of Tatooine use to get across the treacherous deserts.
To travel in luxury and style, he purchased a massive sail barge — an energy-guzzling monstrosity that carries him and his entourage five or six meters above the hot sand on a cushion of antigravity.
Today the barge is a floating party. The crowd from the throne room — even Max Rebo and the band—lounges about in the barge’s dark, fetid hold. Zooming over the Dune Sea toward the Pit of Carkoon, they indulge in the many pleasures their gleeful host has provided. Jabba is not always so generous, so they are making the most of his good mood.
The (admittedly Legends-canon) Star Wars: Essential Guide to Vehicles also mentions two other motives; Speed and tradition
Like many luxury craft, no two sail barges are exactly alike. Most utilize three-chambered repulsor-lift engines to cruise over a planet's surface at about 100 kilometers per hour.