For DIY, there are basically 3 vendors that I use. I won't name them here obviously since this is your forum.
I get VG from one vendor. The cost is $12.95 for a quart which is actually a full quart bottle that is 42 ounces of VG. The price includes shipping priority mail. It is good clean USP VG. I have not really seen it cheaper than that delivered but haven't really looked and probably won't as I like it. The shipping is kind of low end. They just put some bubble wrap around the bottle and tape the top up then stick it in a flat rate Priority Tyvek envelope. So far has arrive without leaking or damage but not good packaging. If there ever is a problem, I will look for a different vendor.
I buy nicotine base and most flavorings from another vendor. They have free shipping on orders over $50 so I just add enough to the order to get the free shipping. The packaging is stellar from them. Always in a box with each bottle in plastic bag and Styrofoam peanuts to cushion them. They ship it Priority mail.
I get some flavors from another vendor. I think they also have free shipping over $50 but not sure because I don't buy that much from them. They offer either first class if weight appropriate or priority otherwise. The packaging is decent but not stellar. The shipping cost is what they pay or very close to it.
The only vendors I have a problem with shipping cost on are vendors that consider shipping a profit center. The shipping cost should be close to actual cost not double or triple the cost. I understand that packaging costs money but this is a business expense and should be included in the price of the merchandise.
Not DIY related, I buy from lots of companies that have free shipping on orders over a certain amount, some as low as $20. I know that the price of the merchandise is probably higher to cover this but I don't mind that. I prefer it usually as I can look at the items and buy them knowing that once I have added $50 or $100 worth of merchandise to the cart, It won't suddenly morph into $75 to $150 at checkout.