I think that you will find the market for "mid-fi" and "hi-fi" gear is quite limited. Frequenting AK can make this fact easy to overlook. I also wonder how you are going to maintain a decent inventory. While the market is small, so is the supply. Good gear at decent prices on CL gets snapped up pretty quick, and it takes a lot of time to cover estate sales and auctions.
Since I retired several years ago, I run a hobby business from my home restoring vintage receivers, speakers and turntables and then selling them (a few units a month). If I had to worry about making money from it, it would be a very tough business. I'm not as fast as a professional tech, but trouble isolation and repair takes quite a bit of time for anybody. You won't find a decent tech for less than $25 an hour (and probably much more, unless you can find a retired guy who wants to do it part time and is willing to work for low $). So you'll have to recover this cost, plus whatever you paid for the gear, plus a reasonable profit...and do this while keeping your prices reasonable.
I'm obsessive about my restoration work....I try to get things as close as possible to showroom condition. Buyers are always impressed with what I have to sell, and I've built up a pretty good reputation...in fact, most of my sales come from referrals and prvious customers now. My prices are at the very high end, and even at that I would estimate that I'm making about $10 per hour for my time on restoration work! The core problem, other than the work being time-consuming, is that while the time it takes to do a nice restoration is about the same for mid-fi as for higher $ gear, the bulk of the available market is definitely oriented towards "mid-fi" prices, If you focus on high dollar gear, you shrink your market dramatically and your inventory turn cycles get a lot longer (which means lower cash flow).
And yes, if profit was my driving objective, I could probably get my hourly profit up to $20 or even $25 by not being so meticulous. I could cut an hour or two off of each unit by not repairing/refinishing the cabinets, detailing the faceplates, tearing them down to clean each pot and switch, cleaning all of the input and output jacks, etc....in other words, do only the repair/service work to get them running properly. But $25 an hour is not going to cover your tech, much less a profit on the unit. And, with this approach, a lot of prospective customers will see your inventory as comparable to what they could pick up themselves at a garage sale.
I know the owners of both of the audio repair shops in Kansas City. It's a very hard business in which to make a living. Most people just junk what breaks and buy something new at Best Buy. They are not looking for great sound quality....just something that plays music and is convenient. And many are going to digital media and wireless speakers for the convenience...not much repair opportunity for this stuff. So, the mainstay of their business is the small segment of the population that are true audio enthusiasts. One shop has improved their business by doing on-site service work on built-in media systems and installing sound systems for churches, schools, etc...but it sounds like you are pretty focused on selling records, selling vintage gear, and doing repair work.
Based on what I've learned with my hobby business, and what I've learned from getting to know the owners of the two local repair shops, if you are going to do it here is my advice (FWIW):
- Start with a spot in a popular flea market, and do it only on weekends. This is when most people have time to shop, your overhead will be much less, you can build up a base of business, and you will get a good sense of whether or not a dedicated shop is viable.
- Have a GOOD website, and market the heck out of it. Have lists of your inventory, good pics, a newsletter with info about sales, new stock, "how to" articles about vinyl, turntables, etc that people can subscribe to. Build a mailing list from your website and from customers who visit your shop, and keep them informed/interested. Offer discounts and incentive for repeat buyers.
- Find a retired tech or someone who can do it part time. DON"T get into the repair business, at least not at first. Use the tech to tune up and service the gear that you are going to put into your inventory.
- Have a standardized checklist of service work done to the items you sell so as to reinforce the value of your stuff vs something they can buy at a garage sale. For example:
- Tested all functions
- Replace any non-working bulbs or lamps
- Performed standard service adjustments
- Cleaned and deoxidized all switches and control mechanisms
- Etc
- Provide a 30 or 60 day warranty (full refund or repair)
- Have information hand-outs covering the basics of setting up and using a receiver or integrated amp, a turntable, etc. Be seen as a helpful, knowledgeable resource....even if the customer doesn't buy anything.
- Keep your inventory displayed well...clean, organized, not stacked on top of each other, etc
Good luck with it.