Can I use nicotine salts in a sub-ohm tank?

Technically yes, but it's not recommended. Sub-ohm tanks produce large vapor, which can deliver too much nicotine at once, leading to unpleasant side effects like nausea or dizziness. Stick to low-wattage pod systems for salts.

Which nicotine type gives a stronger throat hit?

Freebase nicotine gives a stronger, harsher throat hit, especially at higher strengths. Nicotine salts are formulated to be smoother, so they don't have the same sharpness.

Are nicotine salts more expensive than freebase?

Per bottle, they're roughly similar in price, but since salts are often used in lower-wattage devices, they may last longer and be more cost-effective overall.