VapeNW is a good place there. I have ordered from them on several occasions already. But at the same time I won't order everything from there or any other place except for my usual
ejuice source as a rule. Ecigsupply.com has been where I been getting the Innokin Cool Fire IV Plus 70w mods, Freemax Starre and Starre Pro
tanks while VapeNW was for the Atlantis V1
tanks. A seller at Amazon saw the V2 Mega tanks bought recently there while PBDragon has been handling the 510 drip tips lately. Here I will tend to be found "Item Specific" shopping and look up the best deals found.
As for pricing many sites may actually be physical local shops who sell online as well as in a local shop where the overhead will tend to see higher prices often at the MSRPs. That is what keeps them open for walk in purchases while other sites are online only type vendors without the overhead and can see things marked down a bit.
The growing problem at this time as seen with any other type of products sold online is once the popularity grows and the vendors increase you have those who get in it simply to see how much they can rake in! A classic example was seen during the CB Radio craze back in the 70s when every other hooblah dad&mom shop set up a cb shop to cash in once the licensing became free! I knew one couple who traveled all around in a mobile trailer home selling mainly at cb fares.
In the 90s the internet was opened up to bring in the desktop pc boom! where all new pc component sites sprung up for custom builders. And that certainly is only one product in contrast to all the other types of... ecommerce seen since. Presently we have not just the hand held device boom but new mods with Bluetooth capability! And every gas station seems to stocking on Big T brand cig alikes as that also has become a growth industry. While you have some places that remain active advocys others are only seeing the "Cash Cow" for quick cash.