I don't think the durability of the scales is an issue. If you don't treat your razor properly the blade will be gone far before the scales.
The edge holding isn't much different. If you want noticeably longer edge retention you want to be looking at stainless steels and there is probably just one choice for a new razor - Dovo 41, but these days it may cost more than $150.
For more stainless options you have to be looking at vintage - friodur and even better hess 44, which you may be able to find in your price range. However that's a whole different game - you can't just walk into a store and buy those and they wouldn't be brand new, which seems to be important to you.

I think most current dovos would be very comparable among themselves (provided the same blade grind), and likewise most TIs. With dovo you have basically their full hollow grind with the stabilizer, you have the shoulderless grind like on the rennaisance and you have the bergischer lowe, plus the stainless which is the full hollow grind, but different steel.
With TI you have the same c135 steel and two grinds one with a shoulder one without.
The rest is scales and there what you absolutely should stay away from is if they are too heavy (e.g. stainless steel, the real MOP, and on one of the dovo's horn models), or of a particularly funky shape that dovo does on few models.