I will make a custom discord bot with python

Yes, definitely. As long as your provided python script is readable to me, I can extend/customize that.

I will provide you the python script for the bot, you can host that anywhere you like.

Mostly Python, but for complex projects, I might end up using other scripts too.

Don't worry. We can discuss and make something good out of it

Features like welcoming a member, Moderator commands like !mute @A, !ban @B etc..

Complex features are those which are not in directly discord.py library. Like A poll, Leaderboard or a Tic-Tac-Toe game etc.

No, mentioned prices on the packages are a rough assumption. Pricing mainly depends on the complexity of your project.

Sure, I will implement some functions at first and then send you a demo video/ screenshots , which will help you gain your confidence about my work. Then, You can buy my Gig.

Sure, I can host the bot in Heroku for you !