Parcing

[Ovsyanka]

Is it allowed to parse marketplace prices?

[Cathulhu]

You may not use Cheats, automation software (bots), mods, hacks, or any other unauthorized third-party software, to modify or automate any Subscription Marketplace process, the process of Steam account creation or otherwise in interacting with or controlling the processes or user interface of Steam, except to the degree expressly permitted.

https://store.steampowered.com/subscriber_agreement/