How do you define expensive?I purchased this and with really heavy use throughout the year I've only gone through 2 batteries. That's less than $2 for a full years worth of batteries.
They are so cheap that whenever I find a friend who owns a go plus, I just give them 2 batteries. 2 batteries should last a year for 95% of people and cost pennies.
belt it around the sole of your left foot depending on your shoe size or the palm of your left hand while driving. that's when the pogo+ is most useful. when you're at home hanging out, catch manually. the pogo+ only has a 30-40% chance of catching successfully, and won't be altered by your medals. you also do not get the bonus for first catch, accuracy, or curve.
the pogo+ can only use regular pokeballs because niantic is retarded, so if you have 0 red balls and hundreds of greats and ultras, you cannot catch any pokemon with the pogo+, so make sure your supply of these is nice and high.
save normal balls for the pogo+. switch your default catches manually to great/ultra.
make sure you buy a pack of these: https://smile.amazon.com/gp/product/B008XBK7PG/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
there's a really small screw in the back of the pogo+ you need to undo first. if you have an eyeglass repair kit with a phillips, that ought to work. if you don't, the tip of a paring knife or swiss army knife will work too.
the battery will go on for about a month if it's fresh. if your pogo+ was sitting around a warehouse or gamestop it may be low. I advise changing the battery right away just in case.
speaking of battery, assuming your pogo+ stays connected for an hour without disconnecting for no reason or the app crashing (AHAHAHA) it will disconnect automatically to save battery, so when using it for long periods of time, check in on your phone every now and again.
disregarding time, the pogo+ is kind of a piece of shit and will often disconnect for no reason, so if you've got your phone in your pocket while walking around school or work and pass what you know is a stop and it doesn't buzz, or you haven't caught anything in a while, check it and make sure it is still connected.
the pogo+ will prioritize catching mon over spinning stops, so if you're driving for example and there's a mon and a stop next to each other, it'll take the mon. if you're low on supplies and need to resupply, switch off "catch pokemon" in the settings.
in your settings, you can have the thing buzz for mon (green for repeats, yellow for an undiscovered species), stops (blue), both, or neither.
this will help you a lot in getting dust, which is our new limiting factor.
enjoy