Are album covers worth any money?

The original pressings can be. I think the English releases of the Beatles albums are all very valuable. Bob Dylan's 60s records that are conditioned, vintage original pressings are always nice to have. The Rolling Stones records in that period are usually expensive. The bigger the artist, and the better condition, those kinds of LPs will go for more. The Big Brother and Holding Company's "Cheap Thrills" record from 1968 is pretty good. I would say the more original and bigger artists are the way to go.

The best thing to do is to seek out used players because they are always cheap. If you're going to really get into buying vintage stuff, it's going to be expensive. It depends what kind of position you're at. If you're going specifically for the pricy vintage stuff, you're going to have to seek it out more; usually you will have to find those through collectors. If you're at record stores and these places you can get fairly good prices. New stores are almost always a few dollars to low double digits. But new records, especially if you're going to buy them at small record stores, can be a little bit more expensive. I know there's one in Denton, Texas that I saw most of their records were going for $15 and up. You're going to spend $15 or so for a CD, and if it's a band that cares about vinyl anyway and if the buyer cares about vinyl, then you might as well get the vinyl. It's going to sound a little bit cooler anyway.
The perfect quality LP's would cost somewhere in the 100s; older 78s would definitely be worth more. If they are in good condition, old blues and folk music like Old Folk Race recordings, Harry Smith recordings, and the older country music like The Carter Family is probably worth $1000s. Robert Johnson 78s probably go for a lot more. The more historic, the better condition and the rarer would be a good if you can get those. They'll definitely take a chunk out of your pocket book.