I did it in one of my projects.

Following are the steps I followed:

1. Add a field called wholesale_price to the product.

2. Add a role called wholeseller (only if you want to set price by role)

3. Create a product pricing rule:

When calculating the sell price of an order
Condition: Entity has field => Entity: commerce-line-item:commerce_product
Condition: Entity has field => Entity: commerce-line-item:commerce-product: field_wholesale_price

opt A. (to check by roles)
Condition: User has roles: site:current-user, Roles: wholeseller

-- or --

opt B. (to check by user id)
Condition: Add new condition: site:current-user:uid, whateveruserid

Action: Commerce Line Item: Set the unit price to a specific amount: Parameter: Line item: [commerce_line_item], Value: [commerce-line-item:commerce-product:field-adminprice:amount]

Following is the Export of Rule:

{ "rules_wholesale_price_for_wholesellers_of_accessories" : {
"LABEL" : "Wholesale Price For Wholesellers if has wholesaleprice field",
"PLUGIN" : "reaction rule",
"REQUIRES" : [ "rules", "commerce_line_item", "commerce_product_reference" ],
"ON" : [ "commerce_product_calculate_sell_price" ],
"IF" : [
{ "entity_has_field" : { "entity" : [ "commerce-line-item" ], "field" : "commerce_product" } },
{ "entity_has_field" : {
"entity" : [ "commerce-line-item:commerce-product" ],
"field" : "field_wholesale_price"
}
},
{ "user_has_role" : {
"account" : [ "site:current-user" ],
"roles" : { "value" : { "6" : "6" } },
"operation" : "OR"
}
}
],
"DO" : [
{ "commerce_line_item_unit_price_amount" : {
"commerce_line_item" : [ "commerce_line_item" ],
"amount" : [ "commerce-line-item:commerce-product:field-wholesale-price:amount" ],
"component_name" : "base_price",
"round_mode" : "1"
}
}
]
}
}

note : you have to change the value in "roles", which is 6 in my case

I hope this helps.