We're trying to do the guy a favor here, by pointing out that for the cost of several cans of air he could have bought a compressor that comes with unlimited air. Maybe he doesn't realize how inexpensive a compressor can be, so I think we might have done him a favor by pointing that out. And if he already knows how inexpensive one can be, then no harm done... right? If the advice isn't needed, just ignore it.
Nobody's trying to "derail" his thread.