I may have posted this in years past, but the best upgrades I've put on mine for <$100 are:
1. Can of bright yellow automotive spray paint to paint the heads of all bolts that need to be removed for an oil change (hands down, the BEST cheap mod I've done). This makes oil changes a breeze...or at least, makes them significantly less of a PITA.
2. ProClip Mount with Ram Mount Phone Holder (separately under $100 each, but its been a while). I guess this doesn't apply to the folks who have upgraded to one of the aftermarket CarPlay systems.
2. Steering wheel cover
3. Toyota OEM metal oil filter housing; yes folks, its a hell of a lot easier to work with.
5. Dual USB-C port sized to fit Toyota size and replacing the button blank (I think the blank used to be the VSC 'off' button back in the day) Note: I used to recommend the duel USB-C/USB-A port, which I have installed in our Tacoma rally truck, but USB-A is getting rarer and rarer and the LC already has a stock USB-A for stone-agers and Entune junkies.
6.
<disregard> K&N reusable cabin air filter
****changed my mind on this; going back to the stock Toyota/Denso***
7.
<disregard> K&N reusable engine air filter
****changed my mind on this; going to an aftermarket one with nice smell and good pollen filter***
8. I think the Toyota OEM leveling spacers were <$100, but the install was such a motherf*****, I'm not sure its worthy of being labeled a "less than $100" upgrade.
9. Oh yeah...a couple of rubber/silicone key fob covers. You can find them on
Amazon for ~$10 or so.
10. Honorable mention: 200 Series Rear Exit Switch/Handle Kit, I think CruiserTeq sells it, or resells it; search around on the forum. Its about $185 nowadays, but an almost necessary install if you ever plan to sleep in the back and perhaps want to get up to take a leak in the middle of the night, or someone needs to emergency-puke out of the rear hatch.
11. Seat gap fillers...per
@marcus clarkus , $20 off
amazon, standard size. No more bits falling in between the seats and a great place to put the key fob (I am in the crowd that hates push button start). Handy enough that I'd add these to the short list of "almost necessary" upgrades along with the rear hatch exit switch.
I did try installing that "quick valve" oil drain...but, it seemed a little gimmicky to me and I am fine with just using the original plug and a torque wrench.
I think some other posters have mentioned tint and other stuff, a lot of which I have on mine, but none of which was less than $100.
TBH: The absolute, hands-down, best upgrade one can make to any 5.7L J200/LC200 is spray painting the heads of the bolts required to be removed for an oil change. Unless you go with an aftermarket front skid plate or spray paint the heads of the bolts-to-be-removed, oil changes are annoying AF on the 5.7L petrol J200/LC200.