I've used a few different sites to get my mechs from - most of those being clones.
But for prices, I've been pretty happy with
congrevape. Bear in mind those are pre-orders, and if they don't get the minimum amount of supporters, the group buy gets cancelled. And when it does go through, you're still going to wait on your item - but at least they're up front about the proposed ship dates.
I've only made two purchases from Bucky's, but I've gotta say I really like the service there. Long story short, I made a buy in the wee hours of the morning. The purchase went through, but unknown to me, Bucky's never got a list of my items, just the approved transaction notification. The owner emailed me early in the morning to let me know, and had my package in the mail later that same day.