I am trying to fetch data through the shopify GraphQL API and it restricts the cost per query to 1000.Is there anyway that I can increase the cost per call limit call to like 5000.Since I am not able to retrieve the line items in orders or is there any other way that I can get all the line items through GraphQL API apart from Pagination.
Not that I am aware of. I have found it is not practical to use either or Shopify API - that is either REST or GraphQL - as some queries or mutations are better served by the newer GraphQL API while others are still only available in REST or simply allow a net sum of more expensive queries to be run. That's because, as Shopify put
The GraphQL Admin API's limits are based on a calculated cost for each individual query. This is in contrast to the Admin API, which limits an API client's requests based on the number of requests made over a set period of time.
So for queries like "get me 250 orders with all their line items" nothing beats the REST endpoint.
I'd simply use both. Or, as I am doing, use Apollo Server 2.x as an API gateway of sorts where Shopify's REST as well as GraphQL APIs (and other services) are simply data sources. You end up building an API facade (which in itself has many benefits).