Picking Record Albums

I think you have to be a real vinyl fan to do well in this category, but in my area I often see three guys in thrift stores gong through a couple of hundred LPs to find the winners.

I also see these fellows looking at 45rpms to find that first edition of an Elvis title.

Do any of you have experience with records that makes you think they are worth the effort?

I'm not much into music so I have a hard time remembering it all.
I tried for a bit but never made out.  I know a guy that does and he makes some money but his house is literally stacked floor to ceiling with records.  He goes to estates and what not and buys all sight unseen for cheap then digs thru.....

Me? I bought a stack for $1 each because I "knew" they went for $5-&$25 each.
They were the right artist, songs, date, label.....oh....but they were pressed in the USA, not England....so turned out to be worthless.   

After that I decided I'll stick to what I know.

I have about 70 records that I'm trying to sell now. About 50 are from the 50's & 60's and the other 20 are antique Victrola records. Haven't had any luck finding a collector to come appraise them (wish it was as easy as it looks on TV to find an appraiser) and I don't think there are any record shops here in my town. Might have to drive to Austin to get them checked out.

Got a lowball offer from some idiot from Craigslist. Here is how the conversation (via text) went.

Him: "How many records are there in all?"
 
Me: About 70+/-

Him: Would you sell them for $10?

Me: Sure, if you'll sell me your car for $100.

Him: I don't have a car.

Me: