Interestingly enough, boats produced since the early 90s have about all the creature comforts of newer boats, so if you're looking for a tried and true design, like a C34, C36 or C42, most of the "stuff" will already be on board. The two major issues will be age and condition, as always. As many of those of us who have shopped for "not quite new" boats can attest, there are some newer "pig" boats out there, and some fine vessels of an older age in much better condition.
Having owned a now-22 year old boat for the past 12+ years, all I've put in was an upgraded electrical system (new inverter/charger and alternator/regulator). For those who "know" electrical systems, you'd still have to do these two things with a brand new boat, because they just don't make factory boats with decent electrical systems.
All the rest was basic maintenance, necessary on any boat to keep it working properly.
The only "work" left on my boat is the mainsail cover, so if you want to sail a lot then get in mast (or some sort of) mainsail furling.
Happy Hunting.
PS Your "slightly smaller but newer" with the same $$ outlay comment has me stumped, because a new boat is gonna require a lot more $$ for equipment and gear than I think you suspect. Most previously owned boats have tons of material that you do not have to buy, like anchors, chain, electronics, etc. And before folks pipe up and say "Oh you need the greatest interfaced electronics, never buy an older boat with old electronics!!! Yikes, you'll die out there!!!" I disagree. I've heard of more than one skipper who has complained about not being able to see past their Navpod! For your style of sailing, you can choose to get all the bells integrated, but it surely isn't necessary.
PPS Why not pick a boat you like, and find one? For instance, the C34 and C36 are similar boats, but completely different: both are great and have their adherents, and have the same systems. The layouts are critically different, one with an aft head and one forward, one with a larger V berth, one with a larger saloon.