Just one thing to add to the correct answers above--the Deadshot Set is the only UR set granting +1 character level that's still in print. (Meaning you could buy it as Pick Your Purple URs in an token order from TD.) Everything else is Out of Print. However, that doesn't mean you can't acquire it/them. There are numerous resellers here on the forums (see the Token Stores, Token Auctions, and Token Needs and Offers threads) and a couple of major token selling websites where you can buy almost any token. Feel free to shop around for the best price/what suits your needs.
If you only play once or twice a year, picking up a couple of Folios of Might could be the way to go. (They're consumable, meaning they are one use and you turn it in at the beginning of the run, but they will get the job done for not a lot of money.) There are a couple of relatively inexpensive URs that give +1 Level but have a drawback, like Cook's Hat, Ring of Fateful Heroism, and Medallion of Heroism. If you want one token that gives you +1 Level with no drawbacks, you're looking at a relic (Ring of Heroism or Charm of Heroism), legendary (Totem of Heroism, which is a new-ish token and can be acquired either by collecting 40 unique tokens, or buying from someone who made/drew one, but FYI, it is so new that the price is hard to pin down), or going fully down the rabbit hole and acquiring at least two Eldritch items (big $$$--Rod of Seven Parts, Skull of Cavadar, Kilt of Dungeonbane, Boots of Four Winds, and Supreme Ring of Elemental Command).
