Ok, here's the deal: When the new warehouse opens, join, and ride it out for the first year. You have absolutely nothing to lose. Here's why:
It'll cost you $120 for the Executive Membership for that first year. You'll receive a 2% rebate check on everything you buy, except for gas. If you expect to be making any sort of major purchase, (tires, electronics, TV or computer, major appliances and such), you'll quickly spend more than the needed amount to break even on that membership level. Even buying quality wine or good cuts of meat will add up quickly. So ask them to track your spending for you, to see how well you do.
If you find you aren't using it that much, and your rebate check doesn't cover the difference between the Gold Star and Executive Membership levels, (in other words, if the rebate check is less than $60), they will downgrade you to the Gold Star level, at $60 a year, and give you the difference between your 2% rebate check and the $120 you'd paid to be Executive. So in that way, you have no risk.
And if you find flat out you just aren't using it much at all, they will cancel your membership and refund the membership fee at any time during that membership year. You could literally cancel on the 364th day of the year, and get your entire membership fee refunded to you.
As for the Citi Costco Visa card, as listed above, you'll receive 1-4% rebate on all purchases made anywhere, not just at Costco. But you'll also get a rebate on gas bought at Costco, which you don't get if you use a different form of payment. So it's a worthwhile card to have. Note that Costco gas prices tend to be cheaper than anything around, including any cheapo gas stations. And it's quality gas. You need a Costco membership card to buy gas there, so give things a chance. It may surprise you how much you can save.
You need to check out the warehouse, because things are different than they used to be. Yes, there are some bulk items to buy, but there are a lot of non-bulk items available now, too. The fresh deli and organic items are extensive, and are usually in a size that you and your wife can use alone, without having guests over to help eat it all.
And don't forget the quality of what Costco sells is usually higher than anything in the competing market area. But it's Costco, so if you buy something and you just don't like it, you can get a full refund, without complications. As I say, you have nothing to lose.
All in, it's worth checking out. Have fun!
Dave