I think Excalibur has 3 gallon ones for $35. They will be small, maybe 2-3' tall.

Bigger ones are more expensive.

If you go to the Mango Festival at Fairchild in July, they have excellent selections for reasonable prices. They usually have lots of Curator's Choice selections, and "Condo" Mangos.

Don't buy a cheap seedling. Grafted trees are much better and you will get fruit sooner.

Lisa

The Rare fruit council of Palm Beach usually have a plant sale in July also. Might be a good opportunity for you