If I have never dealt with a seller before and do not see shipping costs clearly stated, I always ask about shipping ask
before I bid, by using the "ask this seller a question" feature. Consequently, I receive many e-mails entitled "re: question for seller, item ___."
If the seller does not respond before the end of the auction, I take that as an indicator of the type of seller with whom I would be dealing, and do not bid, no matter how much I want the item. But most of the time I get swift, courteous responses that provide me with a total, and I save these e-mails for future reference. This is why I prefer sellers who set a standard shipping fee and list it in the auction, so I know what my max total will be from the start, even if it is a little high.
Your case was a bit nebulous, as there was the ominous spectre of combined shipping. In that case, I see what the individual shipping is for each item and assume that it will be only
slightly less when combined. If I am willing to bid under those conditions, then I set my snipe. If not, then I hit the road, Jack. I try not to ask an unfamiliar seller about amounts of combined shipping (at least not referring to specific auctions) because I do not wish to indicate my bidding intentions on any more than a single item. If I know a seller, then it is different; there are several with whom I deal frequently and they always treat me fairly. In these cases I do not concern myself with such small details.
Finally, I have found that when it comes to extremely inexpensive items (whose totals typically come out to less than $10, or even $5), many sellers realize they will only see a couple of dollars as the winning bid, so their shipping is elevated slightly from the get-go. In other words, the shipping is built into their profit margin. Though I do not prefer this, I have no problem with it--if it is not exorbitant and it is the only way a seller will make a profit on a $1.99 item. Conversely, I have one seller who sells items at $10 BIN and advertises "free shipping," but I know that the shipping is built into the item cost. But I am willing to pay.
That is what it all comes down to--am I willing to pay? If in doubt, I check before, otherwise decide when setting my snipe.