The $9.99 heat guns work pretty well...until they hit about the 1.5 year mark. First, the switch dies, and it goes into high only. That's the red flag.
Within days it transforms from a heat gun into a flame thrower. You hear the "clink", then if you don't immediately pull the cord out of the wall, flames and sparks will destroy whatever you were trying to heat.
Pull the plug, run it outdoors quickly, and you'll save yourself some fire headaches. Let it cool, drop it in the dumpster, and head back to HF for a new one.
I usually buy them four or five at a time when they go on sale for $7.99. Entirely disposable but worth the $$.