Saw this in the last chance buys, prices range from $300 at Temple and Websters down to $89.95 at Victoria's Basement. Generally goes for around $200+ from what I am seeing, so appears to be a reasonable price for something that Costco is selling. Yes, you'll need to have a Costco membership, so that's something you'll have to factor in if you're not a member.
General description, it's a tiered steamer / slow cooker, from the link:
Slow cook, steam, saute and stew all in one versatile appliance. This multi-purpose unit features two tiers, with a lower cooking pot that lets you prepare diverse dishes. To steam, add the steamer insert for healthy, light steamed fish, veggies and dumplings, and top with the glass lid to help retain heat. Functions include a handy delay start, keep warm and adjustable temperature/time. Get it all done with ease in this multi use appliance.
If you don't like it, utilise the Costco return policy which are quite flexible.
We got it when it was $80 and we use it a bit. If you want to use it as a steamer you'll only have the one tier as the lower pot is for the water. Having said that it's pretty big and seems to give us better results than our old multi-tier steamer. We haven't used it for anything else so can't comment on it's other functions.