different price for service

You will set up and use Items. You can set different items for different prices.

For instance: Lawn Mow, Weed Whack, Weed-N-Feed.

Or subitems:

Lawn Mow:Large

Lawn Mow:Small

You also can use Price Levels, such as Commerical and Residential. Price Levels modify the Base Price of your items, and then you assign a price level to a customer that qualifies for the modification.

For instance, Lawn Mow:Large and Commerical Rate might be different than Lawn Mow:Large and Residential Rate.

 I find it easier to create one item, Mowing, set the most common rate on the item screen

then create one or more price level lists for the custom pricing, and select it when desired on the invoice in the rate block, or assign the custom price level list to the customer on the additional info tab of the customer record

the item list stays short and easy to find the items that way

Menu Edit>Preferences>Sales & Customers>Company tab > check mark use price levels to turn on price level lists. ....    also see Help>Price Level List