guess it depends on how nice that top is on the 80. I have considered the same and found pricing for refret + plek + keep the nibs to be in the $700 range. certainly not cheap at all, but is it worth it? dont know... i just put that guitar in the case and got another one because it was more economical to replace the entire guitar.
I have a 79 LS-50 that was a dog turd when I first bought it(bought off Ebay). The frets were so low I couldn't get under the strings to do any kind of bend. I had a Luthier instal Dunlop stainless steel frets a bone nut and setup. I then later on went and had Jonesy make me a 50's wiring harness, bought a set of Fat Boy Dry Z clones from Harold Wulf bought a Faber bridge and tail piece. I accidentally knocked the guitar over and it suffered a minor headstock crack, so I had a different Luthier "repair" that which he did a piss poor job on.... I have around $1500 in upgrades and repair costs in it. Not including the original purchase price of the guitar.
So to me an LS 80 is definitely worth installing new frets with or without the nibs