Opening Record Store

Looking for advice from my fellow audiogoners...I have the potential to move into a store front that is already being operated as a record store (lps only) and become the new shop proprieter/owner. The owner has offered me the space (rediculously cheap rent) in a good area of town. He has had his store for about 5 years now and has a steady customer base. He will be taking all of his inventory and record storage bins that were in the store.He has a web site set up already and signs out front indicating the name of the shop...I plan on rebranding the shop with name change and interior upgrades. It is not a large space maybe 800-1000 square feet. I have a rather large inventory of my own so my up front investment of vinyl would be minimal. The owner wants me to buy him out..basically give cash in return for his customer base and the potential to get my hands on pretty good collections. I am trying to come up with a fair valuation of something like this and I am looking for advice..What do you think something like this is worth? Thank you in advance.
Don't mind millercarbon: he's pissed off his idol lost the election. Soon, his conspiracies will pollute this thread. I think he's s foot soldier in the cult.
You asked for "tips". I partnered to have owned 3 hi-fi stores getting out in 2001 after 30 yrs of doing it.
Although your store is simpler in product, the thing that you must watch for is "expense creep". You will own the business. Are also owning the building or is he?
Rent can go up, Business regulations met such as fire code and equity clauses. You may be strapped to install the latest fire suppression or widen doorways for handicap access that the owner may apply to you in some fashion.
Differentiated tax codes. State regulations as they apply to transfer of ownership clauses.
New regulations as they apply to sq footage of stores.
10K seems fair to me but I would stipulate payment on a royalty basis to prove how valuable his customer base is within the area itself. If he is "re-opening" somewhere else, he is basically taking his customer base with him if most of his sales are on-line.
I may have missed some stuff but you get the idea.
The killer is in the details....and "customer count".
The Analog Room? I’m hoping a new record shop with higher end jazz and classical lands there. We don’t have many places in the South Bay for that stuff, which is weird given the demographics of the region. 

Sorry in advance if these items are old news to you, I’m just trying to help....

I think putting together a business plan would be time well spent. Working the details out will require you determining profit margins, expenses, and what your breakeven would be in order to make a profit and perpetuate the business. 
Couple of questions/ comments:

1. If you open a business can you capture the customer base without his location, etc? What are you really gaining? 
2. When you figure your profit model, use numbers that reflect an inventory you don’t already own. That should give you a more realistic idea of your cost of goods. 
3. A good, thorough, business plan template will walk you through items to consider. It will be time consuming but worthwhile work. If you struggle with the business plan and hate the process, business ownership may not be for you. 
4. A friend of mine sold many albums in flea markets, music stores, etc. He dealt with stealing, people took advantage of his good nature regarding quality, sometimes swapping their poor album into a sleeve and taking his 33. Video cameras slowed the shenanigans...

5. Ask to see the guy’s books. He should be able to show you balance sheets, statements of revenues and expenditures, and past tax returns.  This is generally required by someone purchasing a business to determine a fair price to pay. His books will also give you an idea of his expenses like utilities, advertising, insurance, salaries and wages if any, and some yet to be determined. 

To be a great deal it should capture your heart and your head. If the numbers don’t make a compelling case, consider waiting for an opportunity that does.

My advice is to carry out DUE DILIGENCE!

How many stock items are in the store? Will it attract enough turnover?

Could you put stock online or on Discogs?