X2. An HD package is a distraction for most use. If you REALLY need a locker, then you'll save up and do a nice OBA +ARB setup.
Yes. High on price. IMO, a LR3 shouldn't be more than $10k...ever. For $15k, you might as well get a few extra Gs and step up to an LR4. Early LR4s are in the ~$20k range, if that ballparks you.
Keep looking. 18" wheels aren't a big thing to swap out. If worse case, you can buy refurb 18" wheels off rock auto (that is what I did for my full size spare). But full service records is crucial and overall just a good, solid truck. But I'm starting to see a lot of 18" wheels for sale 2nd hand. Get em, repaint them (USE PROPER PRIMER, I didn't and that was bad) and slap some tires on.
If you aren't afraid to turn your own wrenches, these trucks are pretty cheap to own and service. Except for the transmission. LOL pay someone to do that. Control arms, I'm hearing about $800-1000 out the door at a shop to have those done. If that ballparks you.
SE trucks are probably the better to go with. If they don't have the Harmon Kardon stereo, then you have a good shot at installing an aftermarket head unit (side note, a stereo that connects to my phone, plays music, and offers hands free is SUPER IMPORTANT to me, so I mention this). If not, I do run a Kinivo BTC480 unit. It works well, just no integration. Plugs into aux port. Oh and the aux port on these is pretty gosh darn useless otherwise. Super bad feedback. Sometimes I miss not having the stupid screen in the middle of the dash, but that dash pocket is SO nice to throw my phone in when I'm driving.
Just keep looking around. I was fortunate, I only had to drive 2 hours to get my LR3. My dad drove 4 hours to get his LR4. I have three friends who bought plane tickets to go buy their rovers (one bought two rovers remotely, like a boss).
For parts, I buy all my stuff from LRDirect.com in england. I have an order coming now. They are usually super quick, however I bought some weird crap and then jerked around the order, etc. But seriously, its so cheap compared to buying stuff here. Stuff from filters, etc to replacement parts. Also the GAP tool has darn near paid for itself in the past 6 months. If I consider the time and frustration of going into a dealer, then it has paid for itself.
Oh, pre-purchase inspection...for ANY used luxury vehicle NOT off lease. You need this. But for real, call around. I was getting serious about a 100 series LC. One shop wanted $400 and "drop it off" (they weren't exactly convenient) while another shop was $75 and "if you call us the day before and setup an appointment, we'll have it done while you wait". So that is a thing.
My LR3 was the "wrong" LR3 to buy according to the interwebs. Its an 05, SE, no HD package, 5 seater, and questionable records for the past 30k. I got it, got maintenance up to date. Put on AT tires. Full scrub down. Taken care of little things broken (trim pieces, a door latch, tie rods, alignment, etc). I'm about to add wheel spacers and rock sliders. And I'll take it out to Colorado in the next 2 months. Before I put ATs on, I had bald street/performance tires (streets on the front, bald performance on the rear, LOL) and I was following around built 4runners. 2 months ago I towed my 109 on a Uhaul trailer a couple hundred miles. Worked really well and I wasn't fatigued. So I'll be towing again in the future with it. Mine had the "wrong hitch" on it with no keys. So I sold it and got the "right" hitch. It had wiring, so good to go there.
They drive so well on the highway. They do drive better than a 100 series on the highwawy, but only by a little bit. A LR4 blows the 100 out of the water on the highway. But it should since its a decade and a half newer.
On the highway, if you can set the cruise at 70 mph, it'll return good mpg.
Try to get one with the trailer setup already. If they've lost the key to the trailer hitch, don't worry about it. You can get new keys easily. Don't listen to people telling you to "cut it off" or anything like that. They dumb. New keys are like, $10 and A LOT less work than cutting anything. Installing the trailer wiring isn't great...but not bad...It was a pain. But its done.
But yeah, start looking at trucks and start looking at plane tickets. Be patient. Took me a month to find mine.