A 10-foot USB cable. Most people use whatever's packed in with their electronics, and it's pretty rare to get anything longer than 6 feet. Having the extra length is really nice in many situations.
It's also one of my go-to inexpensive gifts or part of a care package for someone in the hospital. The extra length there is often the difference between being able to use a device while it's charging or not.
Converting $20 to local currency, I'd probably go with this:
This is so-called "Liubao Tea", a kissing cousin to pu'er tea. I did a review of my first batch(es) and it has rapidly (literally with one round of brews) reached the top of my circulation in teas.
The depicted tea is one aged from 1991 (the one I reviewed was tea stems from 2003) and is of one of the higher grades. A 100g package will set you back about $15 or so at today's exchange rate. 100g is about 15-20 servings, and each serving can be brewed multiple times (even my tea stems can be brewed four times without loss of flavour), so it's quite the bargain.
Save it for a time when you really need something warm, rich, and comforting. It will last forever as long as you store it in a cool, dry, dark space. And personally I think it's a bargain at 15 bucks.
Pet jumping spider.
Honestly 10 star pet. They eat a small bug every other day or so. They look adorable. They will recognize and react to you, and you can even train them to accept handling. They come in a wide variety of colors.
Downsides are that you'll probably end up getting more than one (do NOT co-hab them!), or that they only live for 1-3 years. If you enjoy having the spider though, you can look into other arthropods like tarantulas, or vinegaroons (which look scary, but are harmless and have very sweet dispositions).
A beard trimmer. Shaving sucks and irritates my skin, plus I look like a baby without facial hair. But that's only one benefit.
I have been using a beard trimmer to cut my own hair for the last 10 years which has saved me probably $2000 worth of haircuts (estimating a $25 haircut + tip every 2 months). Not to mention saving about 1 hour waiting at the barber every time. I only messed up once and had to do a buzz cut.
Not luxury, but I keep a small AAA flashlight with me nearly all the time.
Easier to handle and faster to use than a phone light. Also doesn't use phone battery. I clip it on my hat if I need both hands like taking out the trash.
I have an Olight i3T but I would try out the i3T 2. More lumens and better battery efficency.
A small USB-C hub. It has a USB-C out on one end then HDMI, 2 USB-A ports and another USB-C in on the other. I use it as my travel dock for my switch and steam deck, I've used it as a USB A to C converter, and I'll use it to test inputs on various TVs. I've gotten so much more mileage out of this $15 Amazon purchase than I ever would have expected
1L water bottle, especially if it’s insulated. Keeps your drink cool, but also makes it so I don’t have to get up to get more drinks when I run out.
We had some in a car during a trip to Wonderland during the summer. A Gatorade bottle was disgustingly hot while the insulated bottles still had ice in them.
5/7 would recommend
I'm surprised I did not think of mentioning it next to the Preppy fountain pen I already mentioned but a reading lamp! This one is 15-18€ clip-on. It's USB-C (I would prefer standard batteries if there was a model so it doesn't got to waste one the battery is dead). It's lightweight and the brightness (as well as its temp) can be adjusted.
Worth every single cent, imho. I find it so useful that I have purchased two, just in case I need to recharge one.
Oestrogen (joking but also serious)
On a more serious note, a raspberry pi to run pihole and gobble up all the ads for all devices on my home network
Platinum Preppy fountain pen. Often, it's less than 10$
No one needs a fountain pen to write, but writing with a fountain pen is a unique experience. Alas, many fountain pens will cost a little fortune and other will cost a large fortune (what about a 40k$ one?). The Preppy is an exception. It's not the best fountain pen but it's very decent, it's even incredibly good considering its price. For slightly more 25-30$, I would also suggest the Lamy Safari.
Beside that, I can't think of many luxury items under 20. I mean, I can think of a few useful luxury things but they cost more than 20.
A bamboo back scratching stick. I bought dozens back when Pier 1 existed and sold them for 75¢. Most are still around.
The Lady we got ours from isn't showing up at the farmer's marker anymore, but for well under $20, you can make your own corn pillow
This winter's been bad for deep freezes and 4 minutes in the microwave will keep my corn pillow hot for an hour or more.
Silk pillow case. Good for skin and hair.
I carry an arch lighter everywhere. It cost me $15 but saves me a ton in lighter fuel, and you'd be surprised by the number of every day situations that a controlled burst of plasma solves. Opening packages, lighting candles, kills mosquitos in the dark, and it's a fantastic taking piece as mine slots into a zippo.
Only downside is I can't use my zippo for light on the off chance I get trapped in a dark tunnel.
For me anymore, I like to get a nice bag of single origin coffee from a quality roaster.
You can also still get zoo or museum tickets for that in many places. I got a lot of things (probably too many) so I like doing experiences when I can now to slow down the accumulation.
