Trying to help a friend find a used Suburban, willing to spend between $5K and $10K. I'm guessing something in the 5-10 year old range and approaching 100K miles?
Mainly used as a grocery getter and for hauling 4-5 people around town in the Phoenix area, so dry flat roads. Occasionally duty towing a car trailer.
Some basic questions;
1500 vs. 2500?
2WD vs 4WD?
Which years, if any, to avoid?

Thanks for any and all advice!

For reference I bought a Yukon XL 1500 4WD 11 years old 183,000 miles with a dented fender for ~$8,000 . These things hold their value.

$5000 to $10,000 and under 100,000 miles seems more like a 15 years old. $15,000 to $20,000 would be a better guess for the price and odometer combo your friend is looking for.

Sounds like a 1500 would do, unless you want to tow heavy cars on heavy trailers super fast and safely.

This totally depends on if your friend thinks he/she wants/needs 4WD and/or a low-range for some reason.

2000 and later is a pretty good bet. The LS is a good engine give or take upper intake manifold gaskets. Transmissions are pretty good, unless the vehicles has had a hard life. 2009 and later got the 6L80 (6-speed) automatic, which is a much-improved unit. I like the old 4L60 (4-speed) just fine, and my Yukon XL is sitting at 266,000 miles and still on the original transmission with no complaints, but the 6L80 has more gears where you need them and makes the whole experience much better.

I have a friend that got her 2003 Avalanche (which is essentially a Suburban with freaky body work and weird "pickup" bed) to 334,000 miles with no major issues and 50% of its mileage spent off-pavement in snow/ice/mud. Only reason I didn't like working on it was all the dirt and crud that was always falling on me from everywhere.

1992-1999 Suburbans are okay too, but will likely require more love and attention, and intake manifold gaskets are a sore subject on these (unless you get a diesel or a 2500 with a 7.4l gasser).

Incidentally, I had occasion to drive a Penske box van from Chicago to Denver about a year ago. It was a GMC cutaway van chassis with a 4.8 V8 and a 6L80 transmission. The 4.8 is the 5.3'* little brother, mostly the same, just a shorter piston stroke. Prior to this it had never occurred to me that they'd started putting the 6L80 in severe-duty use. Anyways the truck had like 90,000 miles on it but ran perfectly the whole trip. The transmission was glorious and always chose the right gear for everything.

I know I rambled a bit. Hope this helps! Feel free to add more questions etc. if you like.

Thanks, CathedralCub.
So my biggest question at this point would then be, are there any specific years or model Suburbans in the 2000 up to 2007 or 08 that should be avoided for mechanical issues?
She has a home based business but the vehicle is not really seen by customers so looks and age are not as important as a good price and dependability. She has a good friend of the family mechanic who treats her more than fair so repairs are not an issue, she can get practically wholesale price on repairs. She just wants to start with something that won't be plagued with issues, thus my quizzing about any specifics years/models of the suburban to avoid.
She has a 2000 Suburban now that she bought at 120K, it'* now up to 270K miles and time to upgrade. She plans to keep that one as a backup for both her business, and when the family occasionally needs to borrow a vehicle. So, again, going into the shop occasionally is not a big issue for her.
It seems like Suburbans over 10 years old (early 2000s) with 125-150K miles, but very clean are selling in the $5K range. Under 10 years of age and the price starts to double and even triple for similar condition vehicles with almost as many miles. If all she'* getting for double the money is a little newer vehicle, I think she'll lean towards an older one. Any opposing views are welcomed.
Thanks again!

Having driven Suburbans extensively since 1994 (we used them heavily in the military), I would advise you to stay 2000 or newer. They're just more reliable. My family vehicle is a 2004 suburban 1500 with 210,000 miles on it. Only issue I've ever had was the fuel pump (twice), heater/AC blower motor control (the resister bank and the rear switch both went out at different times) and a bad front axle seal. Everything else was stuff that normally wears out, like breaks, bulbs, belts, etc. I found out that the electric fuel pumps use the fuel as a heat sink, so they're far less prone to failure if you never go below 1/4 tank. Wish I'd have known that sooner. I'm no mechanic, but most maintenance is pretty simple. Plus, parts are abundant in junkyards.

We're do for an upgrade in our family vehicle, but I'm keeping this as a work truck for whatever needs done. I've had it since 2010. I was the third owner (second was the dealer who took it on trade) and it had 78,000 miles when I bought it. If I had to do it all over again, I wouldn't hesitate to buy it a second time.

Zac