Welcome back!
The Stratux is a DIY ADS-B "in" box based on the Raspberry Pi and some Software Defined Radio's (SDR's). For around $100 bucks, you can have a reliable weather receiver, which will include whatever traffic is received on the 978 frequency. For around $200 bucks, you can have weather (978) and more traffic (1090) and a good portable battery & power cable. Other options that'll creep into your wallet are special cases, custom antennas, etc. If you aren't a DIY'er, you can buy one of the Flightbox versions https://www.openflightsolutions.com/ that snaps together like Legos. One of the software dev's is also the Flightbox guy, so you know it'll work.
Stratux is developing fast, and has not yet reached version 1.0, so you may hit a snag occasionally. Don't let that dissuade you, the developers are very responsive to bug fixes, and very dedicated to growing the project. They even hope to have AHRS working at some point.
To catch up on the Stratux chatter, check out https://www.reddit.com/r/stratux/
The "official" site is http://stratux.me/ but it lags behind the "real world", for instance it still recommends a battery that some in the reddit forum say is inferior.
For the geek in you, the developer banter is here: https://github.com/cyoung/stratux
The biggest error people make is using a power supply and/or cable that cannot flow the required amount of juice. This can cause a lot of seemingly unrelated issues, such as wifi dropout, radio dropout, etc. Think of it like this: a trickle charger can charge a car battery overnight, but could never start the car on its own. Most USB power supplies and cables are built to trickle charge an appliance, while the Stratux needs a jump starter. Read the comments at reddit to get a feel for what is actually working for people.
If you go the Stratux route, good luck. I've enjoyed tinkering with mine and built a few for others at the airport. with the right power supply and cable, mine works as well as my SkyRadar DX.