Just managed one from Ocean Depths and there are none anywhere... I don't really want it so I want to know how much I should be asking for it.

When I look it up on SubetaLodge it says the estimated user price is 50,000,000 sP!

I'm not sure what the price should/would be, but just an FYI: the prices on SubetaLodge are really not reliable in any way. They tend to be very dated and aren't a great indicator of value on Subeta itself. SubetaLodge estimates the price of the Trident of the Banished One (transformable into Blessed Trident of the Banished One) as 50 mil, but in reality this item sells for about 350 mil.

I'm not saying that Riptide is worth quite that much, but it would be much better to get an estimate from a user who has recently sold one if that's possible.

Riptide is a nice wearable and it's somewhat collectable as one of the legendaries (even if it is pretty useless for battling). Vending is the only way to get it, so it's probably relatively valuable. Best of luck figuring out a price!

You could prolly get close to 75m for it, I don't think many have shown up lately. That being said, it'll prolly also be relatively difficult to find a buyer just because its not a high demand item.

I recently traded one for a Shinigami.