I had the PC membership for exactly one month and will not renew it. In that month I spend close to $400 - it was during the March Madness sale, so I got incredible value and saved a few hundred dollars overall, so it was well worth it for me.

Once the sale ended though I let the membership expire as I had pretty much gotten all that I needed for as little as I was going to get.

So, I would say get he membership and exploit the heck out of it and see if you want to still keep it after the first month.

I think it will be most effective if you have some room on your credit card and if you purchase several items at once. You will keep the service fees down that way too.