Ooo I like this question. Here's my list of unconventional must-haves.

• A tube of chewable pepto bismol tablets
• Ginger Gravol (I eat healthy at home, and eat a good amount of junk food camping, so GI stuff is crucial).
• Sound Grenade—for scaring off bears
• Super long tongs for over-the-fire cooking
• Traeger woodpellets & a smoker tube for my camping barbecue
• WD-40
• Duct Tape
• Aeropress and a french press (didn't get the FP on Amazon tho)
• Power pack. Best thing ever for charging devices in a tent. But also peace of mind for boosting a vehicle, if needed. It can also blow up tires, and other inflatables. Like this one here.
• Niteize Go Anywhere Lite to clip to my dog's collar.
• Rubber gardening gloves. For gathering sappy wood, or gripping wet logs.
• Welding glove(s). For pulling a 600 degree cast iron pan/pot out of the fire.
• Milwaukee flood light. Well worth the money.
• Stainless steel wine glasses
• Torch head and a propane canister. Great for starting a fire when it's wet outside, or still lightly raining.

Get a jump starter. Example:

https://www.amazon.com/gp/aw/d/B00RZXVQSU/ref=mp_s_a_1_1?ie=UTF8&qid=1484210759&sr=1-1&pi=AC_SX236_SY340_FMwebp_QL65&dpPl=1&dpID=51fugIaMe1L&ref=plSrch

I got one recently that has the jump starter, air compressor, USB ports, and AC and DC outlets. I don't know if you can get one that has all that for under $50 though.

a mechanic i know uses this: https://www.amazon.com/STANLEY-FATMAX-J7CS-Jump-Starter/dp/B00RZXVQSU/ref=zg_bs_318336011_10/132-1697626-3478653?_encoding=UTF8&psc=1&refRID=FHAMCZ96Z1KXA6N6K8RR

Got this battery jump starter recently, plan to try it out to charge phones and jump our car if need be (sadly we found ourselves in this situation last year). Price seemed reasonable, plus it has an air compressor!

https://www.amazon.com/STANLEY-FATMAX-J7CS-Jump-Starter/dp/B00RZXVQSU/ref=mp_s_a_1_4?ie=UTF8&qid=1547928324&sr=8-4&pi=AC_SX236_SY340_QL65&keywords=battery+power+jump+starter+with+air+compressor&dpPl=1&dpID=51DLRLDkgVL&ref=plSrch