You’re asking others to write your entire process for you. What you should do is complete the free training on the UiPath Academy web site, to understand how UiPath automations are created.
You’ll need to use the API to put an item into a queue which triggers a job, and that job checks the price. Then you’d have to design an API into your app to receive the alert back from the UiPath job.
“First can i even run a bot just on orchastrator as orchastrator functioning like a server”
No. Jobs don’t run on Orchestrator. They run on servers separate from Orchestrator. Orchestrator just initiates the Job on the other server. We call those other servers “bot hosts.”