Blizzard has decided to keep the experience buff until the launch of the Shadowlands pre-patch. They also added a buff that doubles all reputation gains, which you should really take advantage of!
How can we profit?
There are two main ways to profit from this. We can sell items that are required or useful in gaining reputation or we can spend some time to farm reputation for recipes. The buff is only relevant for Legion and BfA reputation, which limits is a little bit but we can and should still utilize it as well as we can. As for the experience buff we can take advantage by selling items that new characters need.
Sell rep related items
The main way we can earn money selling rep related items is of course by selling contracts. Contracts will be very sought after, particularly by players that have utilized the winds of wisdom buff to level up and are now looking to get their Kul Tiras Flying achievement done. If you are already revered with the 8.2 and 8.3 reputations now is the perfect time to get inscription going to craft these contracts. They should sell well for the next month as players scramble to work on their professions as much as possible. Sadly Legion did not have a similar system and there are not that many ways to generate rep outside of world quests, so there’s nothing to sell to players looking to speedrun it for gold.
Farm reputations for recipes
This is also the perfect time to work on your reputations. If you are missing some key rank 2 or rank 3 recipes now is the time. Your 8.2 reputation in particular for enchanting recipes is a great place to start.
In Legion there are not that many profession recipes that are still relevant that are locked behind reputation. Most of them are only really used to get rank 3 recipes which will most likely not matter much for Legion crafted items. Overall your focus should be on the BfA reputations, particulary in Nazjatar and Mechagon to get the relevant stuff.
Take advantage of the higher than usual activity
Tons of players are going around on new and old characters. Take advantage of this by posting as many items as possible in the catch-up role. Uncanny gear, 8.3 vision buff foods and other items that will be very helpful for new 120s that want to get a taste of the end-game are some of the things you can do.
Hexweave bags can be a great supplement, particularly if you have some garrisons from WoD leftover with a tailoring hut. Bags will always be useful, and they are always extremely popular with new characters.