That old and in that area, anything will have rust. Guess it's up to you on what you're willing to pay. Only advice I'd have is working on something that rusty will suck - broken bolts, etc. But, if your concern is structural integrity, I don't see anything overly concerning.
For context, I bought a 99 LC with 165k for 2500$ . frame looked rusty but upon closer inspection, no holes or structural issues. I used a rust removal wheen and por 15 and it looks pretty good now. Definitely a pita to work on though as bolt will snap. These rigs can be costly if you don't do your own wrench work. If not, id walk away.
I live in Michigan and when I bought mine it was close to that rusty. Nothing but surface rust, no structural damage. The buy it factor in mine was mileage, ownership, maintenance, and price. I bought mine for $4500 with 200k from its original owner who maintained it at the dealer religiously. Had every receipt for the entire life. Being a 98 I assume it has the front locking diff. So that’s cool, but I would put those factors together and take everyone else’s consideration as well. That rust is manageable, but is it worth it to you is what it comes down to.
Mine had less rust, and I had brake lines, fuel lines, fuel tank, and a/c lines all rust through. Plus, you know water leaks, rockers gone, etc. If you're real brave, its on you man. But I'd plan on replacing brake and fuel lines and tank if you want any peace of mind.