We used to (retired 2014).
Do you use the same business/GST # etc for both?
Yes we did.
Business name because there is no point in diluting the brand.
GST because it was all the same stock, and because it's simpler.
The main thing is you have to be very very very careful to remove shop sales from eBay as soon as possible. If not sooner.
We had an employee whose last job of the day was to take down eBay listings when they sold elsewhere. (We also had our own website, and sold on a couple of hobby sites.)
Have you signed up for Managed Payments?
EBay needs your checking account info and secondary identification to transfer payment to you.
Your funds will be Held for up to 30 days at first while you establish your bona fides.
Until you've been selling for 90 days and sold 25 items your payments will be held until tracking shows delivered, or in 21 days if there's no tracking. They can hold the payment for the full 21 days if you're selling in a high risk category. (dotCOM - dotCA seems to go for the 30 days)
You can use Held funds to buy shipping labels.
There are some very good discounts on shipping labels particularly US Tracked Packet.
Ask questions. There are a lot of knowledgeable and slightly bored posters here who love to give advice.
