Well I use Kayak, so I see it total. Nothing else advertises with tax and fees. I mean cars are the same right? At least houses they have to give you a list before you buy. Heck even ebay has people with low price and high shipping. "plus shipping and handling and tax" is standard in most things.
Kayak is certainly good in a number of ways, yes including that taxes & fees are quoted on the search list for air, hotel, or car rentals. Have you tried Matrix Airfare Search tho?
Matrix - ITA Software I really like search air there first for an entire month, and it quotes in total ticket costs.
The current industry approach about charging extra for bags & meals is not popular, but it had an honest beginning; they just seem to be pushing things too far. Different aspects are a matter of opinion I guess.
I generally avoid eBay, because there are extremely few occasions where I cannot get it from a "legitimate" retailer for the same or less, precisely because of the shipping. If I am using eBay, it is usually because I can't find it elsewhere.
That's an overly general statement I think, and wrong. It just depends on what you're looking for. Real shipping costs that the seller needs to pass along can be excessive, especially on heavier items, but the packing & handling costs may be much lower for the cottage business, or just more efficient companies, so the bottom line will vary. It's easy to enough to compare...
Locally available items;
Google or other search engine shopping with shipping, altho many of those do withhold shipping until you get to the end. Really I find this approach from your "legitimate" sources more misleading. I once had a seller that withheld shipping costs so well that I found that I had ordered, having never been quoted a price - and when I did find out the next day, I tried to cancel only to be told that it was too late. I threw a big one over that, insisting they take it back and refund in full, or just refund in full, either way - as they had been deceptive. I did win, but it was a battle as I recall.
Ebay "buy it now" shopping, lowest to highest including shipping. This can be the easiest, just by clicking the right features and looking on the same computer you are on now.
Hint: You probably won't buy groceries online, or liquids, and my recent attempt to find finch food sent me back to Walmart - all heavier items, but cell phone accessories may be the worst thing to buy locally, with your carrier's stores being the highest. Yet most of us get a new cell phone every other year and really - most of us should get a new battery when the phone is one year old. For battery searches, I always include
OEM in my preferences but batteries, car chargers, spare wall chargers, etc. are markedly cheaper on Ebay - and I do like everyone in my family to have a car charger and two wall chargers for each phone. Items coming from the Orient may take 2 or 3 weeks, but for 80% off - cool, as they have cheap postage treaties with the US making it cheaper to buy a new one there than mail one across a state. I still don't understand how some US shippers can ship some things so cheap, but it happens. Just not with 20# bags of birdseed, gallon jugs of liquids, and of course groceries.
Wow, I did get off track there, huh?
Having to add sales tax is a PITA, but at least there you know what you are adding - it is predictable.
There is nothing predictable about taxes and fees and surcharges and all the rest with air travel. It is a constantly moving landscape, both in terms of the types and number of different non-included charges, and in the size of those charges.
Where are you shopping? Kayak, Matrix Airfare, and many other sites are good about quoting total prices on air, hotel, and car rentals, so I don't follow you? No, they don't have luggage fees, meal costs, airport parking rates, airport cafe menus, etc. listed but they are good on the basics.
Maybe you are shopping the providing company sites? Very bad move. It's fine to compare there, but those are the most offensive sites. Not only will they not quote the taxes and fees until they have to, many airlines have devious & evil computer programs that will monitor your shopping and raise fares as you keep looking at choices. At one time you could clear the site's cookies on your browser and try again but they are well beyond that; there is no anonymity any more, unless you go thru a middle site that will keep the secret. Many times I have had Continental Air quote me the lowest price possible, then Kayak quote the same Cont flights for $100 or so less, then connect me to Cont at the lower price to buy there.
"There are more things on heaven and earth, Horatio, than are dreamt of in your philosophy." 
