not being able to zoom with weather proof lenses, and budget lens options?

I have encountered two incidents with my DA* 16-50mm lens when I traveled back to Vietnam a couple years ago:

1) I was on a cruise on Halong Bay and saw water vapor condensed inside internal len elements of DA* 16-50mm when stepped out from air conditioning room.

2) During my shooting, a slight amount of water hit the whole K7-DA*16-50mm system from light rain. I did my worse move by zoom the lens with the thought that it is WR. A couple minutes later, I see water vapor deposited inside of the len elements and could not focus the camera anymore. I also saw water traces on the body of the lens when I zoomed in and out again trying to clean it up later. My K7 could not recognized the lens and treated it as manual lens; however, it recognized the other lens fine. I've let the lens dry out and retried again without success. Later, I've sent it to CRIS in AZ for service and they replaced the circuit board as well as the SDM. Within a year after the replacement, the lens failed again with SDM issue that CRIS sent me the brand new lens for replacement. Kudo for CRIS from Pentax service department for stand behind their warranty service.

I've not noticed the same issue with my DA* 50-135mm lens at all. At least when I stepped out from AC room, the front of the lens has water vapor deposited but no the internal len elements for this particular lens.

My bad experiences with DA* 16-50mm WR issue was with the hot and humid weather. I never see this issue in California weather at all before or after this bad experience.