Some feedback (which I'm sure has already been mentioned).
Easy access to transport - EJ cards in Box Hill is well located. Near Laburnum Railway Station and on the corner of two main roads (Middleborough and Maroondah Hwy). So looking at your location options and target market, perhaps Eltham or Heidelberg
Do you want to be in a shopping centre (ie Knox) where rent is huge (as price per metre)
Definitely need access to low-end inserts, PC's and commons to cater for all markets (not just the pointy end). Sitting at a table and going thru boxes of old cards is very theraputic!
Marketing - Get onboard with a number of junior footy clubs - Fire out some common and low end insert re-packs to kids in Auskick to U12's. The industry is competing with onling gaming like never before. Excellent marketing and follow-up customer service is the point of difference.
Offer a membership with multiple benefits (ie. Member only days for pre-release or specials, or a flat fee annually which gives members free postage).
Set-up a portal or sub-directory on your website which allows members to list/trade cards and avoid the eBay/Paypal fees - Your store could be the conduit where cards are handed over (for a small handling fee).
TV's showing live games or re-runs of classics (via NBATV or similar) - What you save in rent, you can put towards adding value to your customers. (Have a closed store session during NBA Finals to a handful of lucky members etc).
Just throwing a few options out there. Would love to be in your position, but it would cost a marriage.
and also the marketing - of you are doing box breaks anyway there’ll always be some commons and others you can give away to local kids and schools - free enticements to future customers
maybe see if you can scrounge an old card vending machine too, those things were so fun - retro packs , even if they can’t be $4 packs , so many fond memories of coming across those machines in malls back in the day
Something that would be cool especially as I'm useless with youtube would be a booth where customers can open purchases, you then upload to your channel thus getting views
Plenty of great ideas above.
All I'm going to add is no matter what you do,
You need a lot of money in the till every week
To cover fixed costs. So a mixture of stock to
Get s mix of collectors in is important. So much
Of the hobby is online now which is hard for bricks
And mortar businesses.