Tips on Buying Cars: High mileage or old with low miles, ford f150 supercrew, new car price

Question
QUESTION: Just starting to look for a used truck, probably a ford f150 supercrew 4x4.  Have always been in Chevy's but just want something different for a change.  I've been looking and trucks with close to 100k on them are almost 10k less than trucks with 60k.  Will these trucks hold their value accordingly or is there another price point over x number of miles (150K for example).  
Say a 2004 with 62k miles is 23500 and a 2005 with 115k miles is $14k....which is better buy in long run? I only drive them ususally for about 3 years and then I'm ready to drive something different......
Also, at dealership, what is best price to offer from their sticker on a straight out buy, no trade in and I will get financing from my bank.....any other buying tips appreciated....
thanks.

ANSWER: Sorry for the delay Andrew, How many miles a year do you put on?

Most dealers mark up about $4-5000, some use a bucket system, if the price has a 1 at the end (19991.) this means the vehicle is at full asking price, when the end number has been changed to a 2, this means the car has reached 21 days old and has been slightly reduced, if the price has a 3 at the end then the vehicle has reached 40 days and should only be marked up $1000. if the vehicle has a 4 on the end of it, this means it's distressed and is below or at cost and is getting ready to be sent to auction.

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QUESTION: Thanks for pricing tips Danny.  I would probably put on about 15-20k per year at the most-so if I buy anything with more than 100k then I would sell at 150-160k...but how is resell for cars with that mileage?  I'm not big on trading causing i usually know exactly what I want and will buy from private parties often.
2006 ford f150 supercrew with 91k  asking price is 19990....what should I make as offer?  16750. thanks

Answer
Look at it this way, All dealerships have a used car dept because all customers cant afford the new car price, You have the above cust and the below or want to be's, There is always a mkt somewhere when it comes to a price, we sell a lot more cars between 5000-9000 than we do above that target, there are a lot more customers at the 10,00 mark, I would buy a 100k truck because I don't see it depreciating as fast because it has already hit that 100k cutoff, 150k will not hurt the truck, you should get close to what you paid, with less depreciation.
As for the 19990 truck, Yes thats a good offer or starting point.