The barrel and slufoot conversion is about $350ish. Around $200 for the Bergara 45/70 barrel and $130 for parts and labor.

Same projectile selection as a sabotted 50cal and big .451 conicals that wont stabilize in the common 1-28 twist. Plus barrel heat has far less effect on sabotless and they are often easier to load than sabots if you get the sizing right. They shoot sabots quite well also.

Smokeless also opens up way more powder options and the ability to hunt on a fouled bore without the worry of corrosion.