Each place will likely have different packaging and so on, so you will have to price things yourself, but have a look at www.aquariumfertilzer.com
When I am doing something like this I make a chart with all the things I need (including shipping) going down the left side of the paper, and then the names of suppliers across the top. By filling in each supplier's pricing and including notes about things they do not carry I generally end up with the fewest suppliers required to get what I want at the best price. When I have a list that is longer than perhaps a dozen or so things I make an Excel sheet out of it. I do this professionally, arranging supplies for landscape installation. Try working out a list of over 100 plants!
For something like this (just half a dozen items) use the web sites to make up a practice order and include shipping.