I have, a number of times. The answer is yes if we can iron out the normal requirements that make it worthwhile to do.
From the TCE policies page:
Group Buys: To get the most out of a GB the parties involved must consider one or all of the following: order deadline, minimum quantities, prepayment, no Credit Cards, and one location drop ship. By combining all of these we can then expedite the order smoother and pass the savings onto you. GB's requiring individual shipping, different payments, etc. cost more to manage and the price not as deeply discounted. We will honor individual shipping and CC sales of course at an appropriate cost. Minimum order quantity; five or more kits. All GBs are on an individual basis, TCE makes no promise of identical kits or pricing to other purchasers.
I'm happy to consider a GB of five or more kits at a marginal discount. Or you can purchase one at a time now and get a second set of pads with each kit order- up to a $186 value in this case. I'll be happy to come up with a flat % discount (free pads not included) for an order of five individual or more sales.
To me that's not a group buy. It's just a sale price. Look back not too far and you'll see I put up a discount sale price not long ago. A true GB is one that I did recently on a MINI deal where 6 kits were shipped 'en mass' to one destination and paid for by one check. Bulk shipping, one location and no single packaging requirements. And no 3-3.5% CC or PP fee. These fees, advertising costs and the shipping hassles amount to over 5% of the cost in my mind so if a discount were to be 15% without any stipulations it's true cost to me is 20%. I'd love to tell you that you can have these at 20% off and take a huge order but it's simply not going to happen.