I have had great experiences bidding in Cbid, and my humidor is full because of it. Did I win every bid, no way. Did I win my fare share if I bid realistically, YES.
If you are going to bid 30% of retail, just give up now. Sure you may get lucky on occasion, that's great. But it's hare to complain about snipers with such a low ball bid.
I found 70% of retail was a realistic point to set my auto bid. If I got cigars i wanted, I was stoked. If not, I'll just wait until the next auction.
I have the Thursday shipping option. If I won a bid, my later auction, I would start off with higher bids the rest of the week because I could build in the savings in shipping into my bid price. If I would normally bid 13 for a fiver, I'd be happy to auto bid at 15 knowing I was already saving a couple of bucks on combined shipping.
The bottom line is if you don't win, it's not because of snipers, it's because you were not willing to bid higher, and that's totally cool.
Best of luck,