Update readme. Complete details in Cost Estimation section (#366)

## Purpose
* Update readme. Complete details in Cost Estimation section.

## Does this introduce a breaking change?

```
[ ] Yes
[X] No
```

## Pull Request Type
What kind of change does this Pull Request introduce?

```
[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[X] Documentation content changes
[ ] Other... Please describe:
```

## How to Test
*  Get the code
*  Check the readme cost estimation section

Author: elbruno

README.md

@@ -99,6 +99,21 @@ In order to deploy and run this example, you'll need
 > [!WARNING]<br>
 > By default this sample will create an Azure Container App, and Azure AI Search resource that have a monthly cost, as well as Azure AI Document Intelligence resource that has cost per document page. You can switch them to free versions of each of them if you want to avoid this cost by changing the parameters file under the infra folder (though there are some limits to consider; for example, you can have up to 1 free Azure AI Search resource per subscription, and the free Azure AI Document Intelligence resource only analyzes the first 2 pages of each document.)
 
+### Cost estimation
+
+Pricing varies per region and usage, so it isn't possible to predict exact costs for your usage. However, you can try the [Azure pricing calculator](https://azure.microsoft.com/pricing/calculator/) for the resources below:
+
+- [**Azure Container Apps**](https://azure.microsoft.com/pricing/details/container-apps/). Environment type: Consumption Only. The solution uses the Consumption plan, as we don't have specific hardware requirements.
+- [**Azure OpenAI Service**](https://azure.microsoft.com/pricing/details/cognitive-services/openai-service/). Standard tier, GPT and Ada models. Pricing per 1K tokens used, and at least 1K tokens are used per question. 
+- [**Azure AI Document Intelligence**](https://azure.microsoft.com/pricing/details/ai-document-intelligence/). SO (Standard) tier using pre-built layout. Pricing per document page, sample documents have 261 pages total.
+- [**Azure AI Search**](https://azure.microsoft.com/pricing/details/search/) Basic tier, 1 replica, free level of semantic search. Pricing per hour.
+- [**Azure Blob Storage**](https://azure.microsoft.com/pricing/details/storage/blobs/). Standard tier with ZRS (Zone-redundant storage). Pricing per storage and read operations. 
+- [**Azure Monitor**](https://azure.microsoft.com/pricing/details/monitor/). Pay-as-you-go tier. Costs based on data ingested.
+
+To reduce costs, you can switch to free SKUs for various services, but those SKUs have limitations. See this [guide on deploying with minimal costs](./docs/deploy_lowcost.md) for more details.
+
+⚠️ To avoid unnecessary costs, remember to take down your app if it's no longer in use, either by deleting the resource group in the Portal or running `azd down`.
+
 ### Project setup
 
 You have a few options for setting up this project. The easiest way to get started is GitHub Codespaces, since it will setup all the tools for you, but you can also set it up [locally](#local-environment) if desired.
@@ -351,21 +366,6 @@ to production. Here are some things to consider:
 
 - **Loadtesting**: We recommend running a loadtest for your expected number of users.
 
-## Guidance
-
-### Cost estimation
-
-Pricing varies per region and usage, so it isn't possible to predict exact costs for your usage. However, you can try the [Azure pricing calculator](https://azure.microsoft.com/pricing/calculator/) for the resources below:
-
-- [**Azure Container Apps**](https://azure.microsoft.com/pricing/details/container-apps/)
-- [**Azure OpenAI Service**](https://azure.microsoft.com/pricing/details/cognitive-services/openai-service/)
-- [**Azure AI Document Intelligence**](https://azure.microsoft.com/pricing/details/ai-document-intelligence/)
-- [**Azure AI Search**](https://azure.microsoft.com/pricing/details/search/)
-- [**Azure Blob Storage**](https://azure.microsoft.com/pricing/details/storage/blobs/)
-- [**Azure Monitor**](https://azure.microsoft.com/pricing/details/monitor/)
-
-To reduce costs, you can switch to free SKUs for various services, but those SKUs have limitations. See this [guide on deploying with minimal costs](./docs/deploy_lowcost.md) for more details.
-
 ## Resources
 
 - [Revolutionize your Enterprise Data with ChatGPT: Next-gen Apps w/ Azure OpenAI and Azure AI Search](https://aka.ms/entgptsearchblog)