I'm replacing most of the old electrolytic caps in an old piece of test gear and they have used a few 100uF, 50V that are quite large (1.5" x 0.5") for their value and quite expensive. BOM calls for BR100-50, the actual cap installed is a WBR100-50. This is an 85 deg C cap, 2000hr, ESR3.9
, the tolerance is -10 to +150%, but nothing exotic except the price $10.
In comparison Nichicon TVX1H101MAD are <$2, 1/4 of the size, similar specifications except+/-20%
Or if the +150% is important an Illinois Capacitor 157TTA050M (150uF) $1.46
Why are these so physically large and expensive?