Why would people like Owen and Beru choose to live on a barren, arid world like Tatooine? Their is absolutely zero appeal to living their. Its hot and dangerous and moisture farming sounds boring as sh!t.
I assume they're poor as hell and can't afford a starship like most people on Tatooine.
__________________ "Vader's pulse and breathing were machine-regulated, so they could not quicken; but something in his chest became more electric around his meetings with the Emperor; he could not say how. A feeling of fullness, of power, of dark and demon mastery -- of secret lusts, unrestrained passion, wild submission -- all these things were in Vader's heart as he neared his Emperor. These things and more."
__________________ Recently Produced and Distributed Young but High-Ranking Political Figure of Royal Ancestry within the Modern American Town Affectionately Referred To as Bel-Air.
Don't they need those vehicles/droids to maintain their agriculture? And it's not much good blowing all of your earnings on a ship and then getting to a brand new planet with nothing to your name and no business ventures.
I can afford a plane trip, doesn't mean I have much to work with if I moved to America or Iceland.
__________________ “The galaxy must experience the pain of death and the rapture of rebirth as I have. I will bring chaos. It is time for war.”
And heck, a number were brought there as slaves or such.
Some of the species that move there, likely don't mind the climate. Hutts are big enough that dehydration isn't necessarily a concern, Weeqay look quite well set-up for deserts, and so on.
Sure, humans have limits in the desert, but others may look around and say, 'hey, this is a nice place to live, not like all those way-too-humid core worlds full of humans and Duros.'
Not the T-16 no, that was Luke who just used it for racing and blasting womp rats. Plus Owen was able to purchase many droids and they aren't exactly cheap. As I recall he had a total of 3 droids prior to getting R2 and 3PO.
The Landspeeder sure he could use for traveling though, but yeah. I mean if they sold everything, they would have a good chunk of credits to get off world to some place nicer and get a new life, yet they chose not too.
Plus Owen did say
"It's only one season more. This time we'll make enough on the harvest, to hire more hands and you can go to the Academy next year."
So if he can afford the upkeep of his place, the moisture vaportors, the vehicles and droids + while saying he could hire more hands for the next season.
I'm sure that getting off world isn't much an issue and starting a new life somewhere.