The sanding sticks that I use tend to last quite a while and can be used wet or dry.
However, I don't buy them from Squadron but have my wife pick them up for me when she gets her fingernail sanding sticks. They're the same thing and I just tell her to pick them up by color - Black is the coarsest, White is Medium and Pink is fine. You can also get them at Hobby Lobby. They also carry a version of the sanding sticks which are cut into strips about 1/8" wide and 6 to 7 inches long. You get a bag of about 50 assorted grits for about a buck and a half. Buying the strips locally is quicker and usually a lot cheaper.
I still stock sand paper from 220 up to about 1800 for various jobs.
I would make the suggestion that when you are buying tools for your modeling look beyond your LHS and on line Hobby Shops. Granted for a great many things those places are going to be the only place to get the items. However for a lot of the basic items you will use check out the local Craft Stores, Dime Stores, Chain Stores (Wally world, Michaels, Ben Franklin etc). At one Craft Store my wife took me to I found bulk # 11 Exacto blades (100 ea) were about 3 bucks a box cheaper than my LHS. (thats 3 bucks I can now spend on paint at the LHS).