One thing you should absolutely think about before the iPad Pro 2018 launch is what you'll do with your current tablet. Most of you won't want to keep an old tablet lying around so make sure you find a home for it ahead of time.
If you think you might want to sell your current tablet to help pay for an iPad Pro 2018, make sure you dig around various resellers looking for a deal. The best deals usually arrive right before a launch date, but you might be able to lock-in a solid price before that.
Trade-in values on sites like Gazelle and NextWorth will fluctuate throughout the year so make sure you keep an eye on them, even if it's to get a feel for your potential return later this year.
Remember locking in a trade doesn’t mean you need to go through with the sale. You can always back out if you think you can get more down the road.
Make sure you also check out trade-in deals at various retailers and carriers. If your current tablet is in good condition you could get a sizable chunk taken off the price of the iPad Pro 2018.
If your tablet is old and you can't get much in return, you could look into donating it to charity. There are numerous charities out there and many schools will gladly take the tablet off your hands.
If you'd prefer to keep it in-house, you might ask your friends and family and see if anyone needs a tablet or an upgrade.