Road Cycling - Trek 5200 Rebuild Question: Worth it?

I have a 52cm Trek 5200 that is about 7-8 years old. The frame is still in good shape as far as I know. It's never been in any crashes and I've put over 30,000 miles on it since I've had it. I weigh about 135lbs. The paint has some scuffs and there's an area on the inside of the drive-side chainstay where the paint has been worn off from chain rub (previously poorly adjusted chain/derailleur that I ignored for a while). Over the past 18 months or so I've put a new set of wheels on it, new King headset, and new stem. The original 8 spd Ultegra gruppo on this bike is really starting to show it's age and requires frequent adjusting and is not very smooth anymore. I'm thinking of replacing a lot of the parts on this bike with the following: 9 spd Dura-Ace rear cassette (11-23), Ultegra 9spd chain, dura-ace crankset 7700 (9 speed), Ultegra BB, ultegra 9speed shifters with Flight Deck, and dura-ace 7800 f/r derailleurs. I don't particularly have the need to go full 10 speed at this point with 10speed cranks, rear cassette, etc... Any reason I shouldn't spend 600-800 bucks on upgrading this frame? How long can I expect a carbon frame like this to last? To get a similar frame with new all-ultegra would be significantly more expensive and for Dura-ace much more so. What I would do is buy all these new parts for the 5200, get a medium-priced touring/cross bike for touring/off-road/and bad weather riding, and put all the old 5200 parts on an old, used frame for doing errands around the city. That's my plan anyway.

A friend of mine has an original 1st year 5200, he has over 55K miles on it. It's also 8 spd Ultegra and it looks better today than when he bought it. Sometimes I find myself coveting it in it's simplicity and beauty.

Your original Ultegra stuff has done well, Seems like they have improved it over the years so why wouldn't you just refit with Ultegra again or do you think you want to go past 35K on the next group.

I have a 52cm Trek 5200 that is about 7-8 years old. The frame is still in good shape as far as I know. It's never been in any crashes and I've put over 30,000 miles on it since I've had it. I weigh about 135lbs. The paint has some scuffs and there's an area on the inside of the drive-side chainstay where the paint has been worn off from chain rub (previously poorly adjusted chain/derailleur that I ignored for a while). Over the past 18 months or so I've put a new set of wheels on it, new King headset, and new stem. The original 8 spd Ultegra gruppo on this bike is really starting to show it's age and requires frequent adjusting and is not very smooth anymore. I'm thinking of replacing a lot of the parts on this bike with the following: 9 spd Dura-Ace rear cassette (11-23), Ultegra 9spd chain, dura-ace crankset 7700 (9 speed), Ultegra BB, ultegra 9speed shifters with Flight Deck, and dura-ace 7800 f/r derailleurs. I don't particularly have the need to go full 10 speed at this point with 10speed cranks, rear cassette, etc... Any reason I shouldn't spend 600-800 bucks on upgrading this frame? How long can I expect a carbon frame like this to last? To get a similar frame with new all-ultegra would be significantly more expensive and for Dura-ace much more so. What I would do is buy all these new parts for the 5200, get a medium-priced touring/cross bike for touring/off-road/and bad weather riding, and put all the old 5200 parts on an old, used frame for doing errands around the city. That's my plan anyway.Why waste money on all that DA stuff when you are sticking with ultegra shifters? I'd spend the money on DA shifters and ultegra the rest of it. Wouldn't even mess with the cranks,but maybe replace rings if they need it. The frame is good for as long as you want to ride it so long as her is no structural damage.

Any reason I shouldn't spend 600-800 bucks on upgrading this frame?
Do you want to keep it? Would you rather have something else? Does it still fit your needs and excite you? If all answers lead to you keeping it, then yes, 6-800 bucks is money well spent.

55/Rad