When I put in the config a block for example the hay_block that block is a good protection I want to know that when the player craftea that block and places it comes as protection and I want that only when they buy only with that block can protect

I think you mean to set a unique id for special hay block so only
the hay block type they buy is claim and not the crafted one?

meta-name: §a§LBIRCH §2§LFORESTER
meta-lore:

• §a§L■§2§l■§a§L■ §a§LBIRCH FORESTER §a§L■§2§l■§a§L■
• §fTo use, sneak place on grass/soil.
• §fCreates §a60§f radius mixed Birch forest.
• §fwith flora, and a few Endermen.

Give it a meta name and or lore.
In the above example only birch saplings with that name and lore will be the Pstones,
Not birch saplings from trees or shops that just sell plain 6:2 id item.

http://preciousstones.shoutwiki.com/wiki/Field_Flag_Reference#meta-name

meta-name: §c§LHAY BLOCK FARM PROTECTION
meta-lore:

• §a§LNo you cannot just rename a hay block
• §a§Land place it.. it must have this lore also!

If you use lore/name for block and sneak-to-place: true?
PLEASE use the new 10.7.1 field flag

sneak-to-place: true
sneak-to-place-only: true

Or they will break if player does not sneak and place.