I found another penetrating lubricant called PB-50 (by the same
company that makes PB Blaster). It is massively cheaper than LPS-2 and
is sold for $2.50 per can at Home Depot. The can is slightly smaller
than LPS-2, but the price difference more than makes up for it.

However, this PB-50 does not disperse widely, it shoots a jet of it.

So, there is no good alternative to LPS-2.

I agree with the opinion expressed here, that buying LPS-2 by the
gallon, and using spray bottles, is the best bet if I need to use a
lot of nondrying, easily sprayable, penetrating rust preventative.
This is what I will do. I have a large quantity of steel, tool steel
etc. I will sell some, but I will keep a lot and I want that steel to
stay clean and not rust.

i