Money
In DotA 2, all heroes / champions are absolutely free. It doesn’ t encourage anyone to spend money to‘ buy’ characters or spend many, many hours trying to get enough points to afford another character. You can however receive items to your character look better in the game. You can also buy announcer packs and other small things. These items are awarded after a game and can be also purchased.
Additionally, in LoL there are masteries and other things you can earn as you play. These give some people who have played for a long time an advantage over a new player starting out. This in a sense make DotA 2 fairer as it doesn’ t matter if you are starting out or if you have played for a long time, you still have a chance to win the game.
Mechanics
As both games are of the same genre, their mechanics and gameplay are quite similar. DotA has some things that LoL lacks. For example, there is an ability to‘ deny’ minions / creeps and towers / turrets. This‘ deny’ kills the object, preventing any gold or experience to be awarded to the opponent. This is useful when you want to prevent the enemy from getting more and more gold to spend on items. There are also many techniques such as pulling creeps / minions. In DotA you can also buy back with gold after death.
There is something called recall in LoL where you can freely teleport back to base. This makes the game easier but some may also like the fact that without a recall, being unprepared for battle can result in a larger penalty of walking back to base. There are also Town Portal scrolls in DotA for you to teleport to any friendly building which is a nice feature. Also, there is a courier to deliver items from base to you. LoL has a variety of items but they are mostly stat boosters. DotA has some active abilities that come with items making the item you choose to buy quite important.
The shop is more organised in LoL but there may be further improvements for DotA. DotA also has a suggested items list which helps new players choose an item to buy.