I think the closest thing that'll get to your budget and your criteria is a 510 dhv, but you'll need to install SS coils and you'll have to either own a box mod that can be used with TC (preferally AF,red panda or dna mod), or really get to know your vape when using wattage, meaning you should know, and learn to feel while drawing, exactly when the heater starts to glow, because AFAWK, SS316L degradation starts around 500C (good luck lol).
About the paper, I wonder if they changed the coil after each experiment (or even for each case) or used same coil for a period of time (beside the 1st exp that they had to change to different ohms). My guts tells me they switched after at least each experiment, if not after each case, which leads to this point:
I doubt that the researchers did a burn-off before the experiment; that might change the results importance significantly and might make this paper irrelevant as everyone who installs a coil either do a burn-off or have 0 experience. You can also see in Fig 2(d) for example (and at other Figures there) that the number reduces as time goes by, which let me to thinking no burn-off was done at all and a fresh coil was installed each time.
If I'm correct, the question should be if a coil stays in good shape after a good burn off and right usage, or more precisely, when does the metal oxide layers that got formed get damaged? (as I said above, AFAWK with ss316L, the layers starts to get damaged around 500C, but if I recall correctly Kanthal A1 is even better in that regard and can be used above 500C without degradation, which can be enough for our usage, but it depends on the heater.)
As the quoted paper stated:
One finding of interest was the steep decrease in the TNC over the course of the sampling period. This effect was consistent across the various operating conditions (power, resistance, and duty cycle). A possible explanation for this observation may be the formation of a metal oxide layer on the surface of the heating coil (Boggs 1971; Prescott and Graham 1992; Sauer et al. 1982; Sundberg et al. 2004). When Al alloys undergo oxidation, they develop layers of protective alumina on the surface (Sundberg et al. 2004; Boggs 1971). Any breach in this layer allows for oxygen to contact the metal underneath that layer, resulting in the formation of Fe oxide (Boggs 1971). As this layer is formed, further metal evaporation, and particle generation, would be decreased.