Used 2001 Allez Comp with the full Ultegra group.. lets say 1000 miles
VS
New 2004 Allez Sport, tiagra w/ 105 rear.

Given good fit and similar price which setup would be the best value? This is really a hypothetical question since I don't have a specific used bike in mind. I really wanted to get opinions on the value of a used bike. I have done some quick price checking and it looks like I can get a new bike with a Tiagra set up (and I am assuming similar quality wheels etc) or a 3 year or so old bike with Ultegra (and again assuming higher quality wheels etc) My questions is what would be the best value given my intended use and tendencies as listed below.

The bike will be used for training and Olympic tris, probably a few 50 milers maybe even a 100.
I tend to be moderately rough on my toys.. I don't baby them, but I am not crazy.
I tend to not upgrade things unless they break, to the extent that I will put up with something making noise or not working 100% until it is officially broken. Based on past history with mountain bikes I use a bike until it is done... fixing only what breaks. When it seems everything it a little off I get something new, this usually takes enough years that most components have evolved 1 or 2 generations.
Stuff that makes noise drives me crazy.. but by nature I am too cheap to fix it.
I am comfortable doing minor repairs & maintenance.
I certainly do not mind buying used (In this case I don't feel like I know enough to ensure I am getting what I want)

So the question boils down to where is the best value. How long does a road bike last (say 800 miles a year tops) with regular maintenance? 3 years? 5 years? 8 years?
Do 3 year old ultegras perform like new tiagras? Do 4 year old ultegras perform like 1 year old tiagras... you get the picture. Same with wheel sets, what do you get in terms of performance and longevity when you jump in quality two levels (Level 1 -OK, Level 2 -Good, Level 3 -Better)

Thanks

Used 2001 Allez Comp with the full Ultegra group.. lets say 1000 miles
VS
New 2004 Allez Sport, tiagra w/ 105 rear.

Given good fit and similar price which setup would be the best value? This is really a hypothetical question since I don't have a specific used bike in mind. I really wanted to get opinions on the value of a used bike. I have done some quick price checking and it looks like I can get a new bike with a Tiagra set up (and I am assuming similar quality wheels etc) or a 3 year or so old bike with Ultegra (and again assuming higher quality wheels etc) My questions is what would be the best value given my intended use and tendencies as listed below.

The bike will be used for training and Olympic tris, probably a few 50 milers maybe even a 100.
I tend to be moderately rough on my toys.. I don't baby them, but I am not crazy.
I tend to not upgrade things unless they break, to the extent that I will put up with something making noise or not working 100% until it is officially broken. Based on past history with mountain bikes I use a bike until it is done... fixing only what breaks. When it seems everything it a little off I get something new, this usually takes enough years that most components have evolved 1 or 2 generations.
Stuff that makes noise drives me crazy.. but by nature I am too cheap to fix it.
I am comfortable doing minor repairs & maintenance.
I certainly do not mind buying used (In this case I don't feel like I know enough to ensure I am getting what I want)

So the question boils down to where is the best value. How long does a road bike last (say 800 miles a year tops) with regular maintenance? 3 years? 5 years? 8 years?
Do 3 year old ultegras perform like new tiagras? Do 4 year old ultegras perform like 1 year old tiagras... you get the picture. Same with wheel sets, what do you get in terms of performance and longevity when you jump in quality two levels (Level 1 -OK, Level 2 -Good, Level 3 -Better)

Thanks i own a allez elite with 105 group set ive put about 8000kms about 5000miles on it in 12 months and its still running great it does not have that much wear on the componants and looks like it will last for some time yet i clean and re-oil my chain about once a week i believe if you do this it will last alot longer as dirt and muck will kill your driveline in no time thats something you dont know about when u buy 2nd hand even if the bikes only got 1000miles on it if it has not been well cared for it may be the same as a bike with many more miles on it that has been looked after just buy the bike that is in near perfect condition as you can get i believe the bike with better componants that has been looked after would be the way to go

As to how an older bike with higher-level group compares with a new one with lower-level components, I'd think it's kind of a subjective decision. New 105 versus 5-year-old Ultegra? I'd probably go with the 105, all other things being equal. New Tiagra versus older Ultegra? Tough to say, but I think I'd go with the Ultegra assuming it's in good condition. In your example you say the used bike has just 1,000 miles on it. That's almost same as new unless those were really abusive miles with no maintenance.

One other thought is that a bike fitted with higher level components usually has a higher-level frame. Not always true, I realise. Sometimes companies will use the same frame for several models with different component levels to hit several price points. But generally speaking ...

You also ask how long a bike will last if you ride 800 miles per year at most. At that level of use any decent bike will last pretty much indefinately, assuming decent maintenance. I have a 6-year-old Allez with more than 17,000 miles on it and everything on it works like new. All I've ever replaced are tires and the chain.It isn't anywhere near the end of its lifespan. I have another steel bike that's much older and still has many years of good use left in it.

I would go with the Ultegra personally but, which of the two bikes moves you more? Whichever bike you wind up with will probably have the componants replaced/upgraded. You only live once so you need to pick the one that will make you the happiest. Proper preventative maintenance will ensure long life for your bike and it's componants.