Depends on many factors. I have seen shops that are basically a closet with a bench top press and so they have very low overhead.
I have seen guys put $30,000 into a state of the art shop. What are you looking to do?
We had many miscellaneous items (Q-scale, spinner, bevel sander, etc.) before opening a few months back so it was mostly a matter of hunting down good prices on retail display items. (craigslist is great for this) Ended up buying a nice press and so that was a big expense but imo it is absolutely essential.
Bottom line is you can do it on the cheap and try to keep upgrading equipment and this is probably your best stategy. Depending on your lease you can open the doors to a decent shop for $10-12k...not including inventory.
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ALL STAR BOWLING & TROPHY
LANGAN'S ALL STAR LANES
WALLED LAKE MI