I am sure some will beg to differ with my thoughts, but a Sabre 38-2 and J40 are not even in the same genre of boats. Build wise, probably equal etc. BUT,the J 40 has a PHRF in the 70-90 range, the Sabre 110-130. At least locally for my, 2 class's slower on the Sabre.
The Sabre I would call a fast cruiser to slow Cruise/racer, the J a fast cruiser/racer into the slower end of the race/cruise arena.
So which do you want? Boats equal to the Sabre to me anyway, would be the Tartan 37 of that vintage, Jeanneau has a Sun Odssey 37 and 40 and maybe the sunshine 36/38. Oday used a Jeanneau design, IIRC the 39 or 40 from the 80's relm. Beneteau or Catalina to name a few other brands, but a bit lower in quality, but on par speed wise. You could get a newer version of the Jeanneau/beneteau/catalina over the sabre or tartan.
I you want more racer, look at the J 37 or 40/120 ie newer version of the 40. I have seen some 40's on par price wise with 120's. Jeanneau Sunfast 37 or 40 are race versions, taller mast, more sail deeper keeps, upgraded hardware over the SO versions. Beneteaus First series, the 40.7 comes to mind here. Possibly the C&C 120 in the older models may or may not fit your budget too. More than likely not. The C&C 110 in fiberglass back to 98 and up to 03 can be had for the low 100-120 range, PHRF in the mid 80 range.
Frankly, you need to decide which style of boat you want, as I said before, you are asking about 2 boats with equal builds, but WAY different sailing characteristics. I personally would be looking at the J's, first 40.7's etal before a sabre. Those are my style of boats vs the sabres. Interior wise, I have yet to see a J keep up with the Sabres. Speed wise, racing etc. no comparison. You might also look at the Farr 11.8? or some such design that JeffH on here has too. Fits the J40 race/cruise relm of boats too. The 40.7 is also Farr designed and has done well in ocean style races.
She drives me boat,
I drives me dinghy!