Depends on your brand. You can start with 100 you can start with 100000. Do your research and make a budget
Like justin said itll be different for everyone. We bought a DTG printer at the start so our costs were a lot higher. But my advice to anyone is make a budget for 3 months and make sure you have all the money you need to buy stock, marketing, giveaway etc for those 3 months. Now take that number you just came up with, and double it.
Thats how much you should have. Nothing worse than simply running out of money or having all your cash tied up in stock when you need money to fix your website or to buy new stock that will sell much better.
And to answer your question we started in the 5k-10k range.s
Creating a Flyer for my re-release this summer
The bottom with your brand info doesn't exactly look the greatest... Try cutting the image and just having your logo/info over a white background. I think itll look much better.