There is a limit of 1 purchase per day for gifting, a limit set by the game.
Everything else other than spins doesn't have a limit and can be done by trade, as long as you have gold for the tax.

You must at least be Level 75 or Prestiged to receive Gifts.
You must at least be Prestige 1 to trade for crates.

For gifting, you will choose 50.000 Gems worth of items from the shop, such as:
- Crates
- Spins
- Shards
- Scrolls
- Emperor Keys
- Potions Boosts

Attack on Titan Revolution 50.000 Gems