The early 911 values' push effect has been going on since 2000 & even back into the late `90's to some extent, with the expected pauses or flattening at recession times. When the early SWB & LWB 911s pushed into 6-figures & some into mid-6's - then the 914-6s first, & 73-74 2.0s, 74 LEs etc. next began to rise.
So not only are 911s taildragers, but are also "the tail wagging the dog" when it comes to 914 values.
Similarly, with the 4-cylinder 356s reaching even higher heights than early 911s, that drove prices for both 4 & 6 flavors of 914s as more accessible early air-cooled collectable Porsches. Remember that you could get a Speedster, Coupe or Cab #1 cars which now sell in restored & even restoration-resurrections for 2-300KS - which in the 1960s-70s for a couple of thousand dollars!
So never say never, about if 914/4s would ever pass $100K at some point - as we're 1/3 of the way there now!
Also lately with the early 911 prices plateauing, the 914 values seem to follow suit & have flattened out their rise from the mid to high $20Ks for a Concours level 73 914-2.0 in 2009-10, up to the early to mid $30Ks & relatively flat since 2015.
https://www.hagerty.com/apps/valuationtools...Porsche-914-2.0 ^
see the chart at the bottom, & revise the search for any other MY & engine/sub-model you like.
Similarly, the factory 914-6's went from the $50-70Ks to $90-100K+'s in the same period, & have been flat lately.
Part of this is the fickle nature of what the big collectors think is hot - or will be - & what they pine for, as well as the economics of the purchase/value relative to other options. So later 70's 911s are feeling the same value push & interest lately.
Also - while the top end #1 cars rise or pause, so do the #2-4 cars, as well as resto-mods, conversions, etc. - just at a lower level than are the "hen's teeth'" #1 all original numbers matching cars - with an unmolested, low mile, all original & never restored #1 exceeding their value curve by quite a bit.
.... & I do mean "ALL original" - not the ubiquitous "all original, except..." cars too often advertised at top prices. If well done they may have a good value, but not the top dawg all original values.
Probably at this point while some "virgin all originals" are available, as well as undamaged & minimally rusted/repaired & accident free "all originals" with restos requiring minimal body work, both commanding top values - those "originals/numbers matching examples with more rustoration &/or accident repairs in the resto will lag a bit below those. However, in the future as supply of good #1 cars dwindle & if demand for them keeps up or grows even more, then even those will close the gap on the all originals over time.
Similarly, the resto-mods, 6-conversions, Subi-conversions & V8-beasts, etc. will command good values relative to the quality level of their work done - but at a level below the originals at any of the #1-4 quality levels.
So at some future date TBD, the 914s - both 6 & 4 - may reach the recent highs of the early SWB & LWB 911s - but by then they too will have escalated in all probability.
However, the early SWB & LWB 912s & 76 912Es will probably stay within close value with the more desirable 914/4s (74 LEs, 73-74 2.0s, 75-76 2.0s, 72 914/4 1.7s, & very early production date/number 70 MY 1.7s) - as they are today.
The 914-6s are & will remain above those 914/4s & 912s/912Es & closer to the early SWB & LWB 911s, & maybe even stay comparable to the lower end 911Ts & 911Ls of that era - or perhaps even more than them, if more collector folks finally figure out that the 914-6 is both more rare by numbers produced & handles so much better than those base level taildraggers!
That's my opinion of the forecast anyway, & that of many other collectors, insurers, etc.
So my word of caution is - whatever model/engine 914 & condition level #1-4 that you have - make sure to recheck the current values & adjust your insurance coverage accordingly ever year or two - so that you're not cut short in case something happens to your baby!
PS - FYI - my 914 is an early 73 2.0 with the Appearance & Performance Groups of options included in the base price & marketed in late 72 & early 73 as a "914S" "Trim Package"* (similar to but not with the +/-1000 limited numbers of the 74 914-2.0 LE Trim Package*), & it's a matching numbers car, but it has accident & rust damage which needs to be repaired in my resto. So even though I plan to keep it all original, taking it back to the OE Light Ivory L80E paint, with a few of the optional dealer accessories sold back in the day (e.g.: the AMCO Porsche+Audi approved Porsche Crest shift knob, which has been on it since I got it as 2nd owner in 12/75), as well as returning it to the factory supplied center console, fog lights & Fuchs 2L alloys which were removed by the selling dealer before the OO bought it new - it won't rank in the top class of very low mile all original, lightly restored or fully restored 914s with less rust/panel damage to repair.
For those wondering about my 911S & LE comparison as a "Trim Package" - here is a Wike definition for it below, & there are other definitions out there too.
https://en.wikipedia.org/wiki/Trim_packageCheers!
Tom
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