Problem
The price for the task appeared on the estimate as $1800 instead of $2000. This was due to the membership type discount applying a greater discount of 5% or $1800.
Solution
When an item is discounted by a membership, the system always considers the greater of the two discounts, applying the highest one to benefit the customer. If you do not want to apply a discount to a particular item, you have multiple options.
Remove the category from the membership discount
Go to Settings
> Invoicing > Membership Types.Find and edit the membership type in question.
Under Basics, look for the Discounts section.
Change the discount percentage of the Category, Business Unit, or All services to which the task in question belongs.
Make sure to check the box Do not discount if the percentage is set to 0%.
Save Changes.
On the individual level, remove the discount from the item within the Pricebook
Go to Pricebook.
Find the item and click Edit.
Make sure the item does not have a membership price added. If it does, remove the membership price.
Or, uncheck Allow Membership Discounts.

Save Changes.
After verifying these have been completed, it is best to remove the item from the invoice/estimate and add it again.