You can never have too many tools.
I agree. My XYL may differ.
I have a heat gun that was bought for $5 from Harbour Freight Tools. We have a few stores here in town. Other stuff I've gotten from there: black plastic ties, digital multimeter, etc...
I recently bought a LCD frequency counter from an ebay seller. Sure, I can use a general coverage receiver for verification, but I wanted to make it easier to know for sure. Plus, this can come in handy for those radios that do not have a display.
One tool I want to get is a signal source. Or maybe build one myself. Maybe building a crystal oscillator for the signal I need would work...
Hopefully, you are not far from finishing your transmitter.
Recently, lost a nut for my MFJ key. Consequently, it was a good excuse to get a better key... I got a Nye oval key from Morse Express.
73 de Daniel, KK4MRN