i was in the same boat, wanted a LS for a few years, finally bit the bullet and sold my honda and took a loan and got an '00 V8 w/ 20"s at a good price. for me it was a mixture of the looks/luxury of the car (upgrade from a honda, no doubt) but also i promised myself the next time i bought a car, it would be the car i WANTED, not whatever was necessary to get me fromt point A to B.
your question of "is it worth it" depends on your lifestyle and income. if you need to take a loan out like i did, can you afford the monthly payments, plus insurance, plus maintenance, plus gas? and the LS eats up gas like it's no one's business so be prepared for that. are you commuting to work everyday or keeping it more for pleasure? how many miles do you expect to put on it per year? i'm a bit fortunate in that i walk to work, as my apartment is on the same street as my employer, so i expect to put anywhere from 4k-8k a year on it, which balances out some of the high gas & maintenance costs. but if you are looking to put the standard 12-18k a year on it, you have to figure anywhere from $1000-$2000 a year in gas, probably $500-1000 in maintenance, not to mention your other basic costs.
just do the math and see if it works for you. it is a beautiful car and even though i have less money to work with now, i don't regret the purchase at all, cause i knew deep down it was the one car i wanted (short of a Viper, but im going to have to wait for my mid-life crisis for that one).