You ask a tough question. The answer really depends upon your taste (see Bill?s post) and how long you intend to own an airplane.
If you plan to keep the plane for say seven (7) to (12) years or until they take the keys away from you could well be better off buying a solid but scruffy lower time airframe with a high time engine. You can then do the overhaul and know what you have. You can put a paint job on it and enjoy it. You can put in a few new avionics items and use and enjoy them. The minute that you write the check for an ?upgrade? or major repair you have lost 40% to 100% of its? intrinsic value. A case in point is your unwillingness to pay a premium for a 0 time engine (I don?t blame you at all, just making a point.)
Now if you keep the plane for a long period of time you can prorate your upgrade, overhaul and modification cost over the time that you have owned the plane and it doesn?t sting so bad.
On the other hand, if you like shiny and don?t plan to keep the plane for more than a few years you are better off to shop harder and longer and find a plane that in addition to being shiny is solid mechanically, well equipped and with a mid time or less engine. You will get a better equipped and higher quality finish cheaper if the seller paid to have it done.
The two thing that you need when airplane shopping are patents and discipline. Know pretty well what you are looking for and take the time to find it. Don?t get sidetracked and have patents, the right plane is out there. I have spent as much as a year looking for the perfect airplane and I have purchased the first airplane that I looked at. Most of the time it worked out very well, a time or two it didn?t.
I know that you are now in the phase of the buying process of deciding what you really want to buy. This is tough, particularly for a first time buyer. At least making a mistake in buying a 150 won?t put you into chapter 7; if it will you need to find another avocation. Just keep shopping, looking and learning and when you see the right plane you will know it.
Good luck on your journey.
