Beater guns are my favorite. Adjust the price, and buy the gun, I say. Finish has a LOT to do with book value. Worried about the inside? Take it apart before you buy it. What's the big deal? Most of my guns are ugly, or on their way to being that way. I don't buy them as an investment (most of the time). I buy them to shoot the Hell out of.
As for gun value period, or any collectible, it is only worth what someone will pay. I don't care what a book/person says the value is. I think if you really like the gun, the setup, the paint job, then you won't really care about resale value and such. As long as YOU feel you are paying a good price.
For me it affects the price and the decision. If it's a "professional looking" job, I have no issue with it. The term "rattle can" makes me envision a less than quality job.
Think it all depends on the product applied (GunKote, DuraCoat, Brownell's products, etc.), the quality of the refinish job, the purpose of the firearm (tactical, CCW, etc.), the type of firearms, and my intended use of the firearm moving forward.
I will NOT perform, nor will I purchase a heirloom quality or collectible firearm with a refinish job, but for a good working gun such as a waterfowl gun, kid's first firearm, PDW, CCW, tactical piece, etc., I see no issue because of their intended use.
I almost bought a Remington 700 22-250 that was painted (not well) camo, but before I got there with the money a guy working at the shop bought it. I like to work on my guns, so it would have been a great project for $250.
Depends on the gun. Need more info and a pic for anyone to give a decent opinion. Just about all spray finishes will chip and scratch off at contact points. If it's gonna be thrashed about anyway and the price interests you, go for it.
I saw a used NEF single shot Turkey gun with an extra full choke and sights, sprayed in rattle can camo for $40. As I tried to get the attention of the shopkeeper, I realized another patron was already negotiating a purchase and bought it for $35. Would have been nice for rainy fall or spring mornings on our lease. Conversely, I wouldn't be interested in an AR or bolt gun with the same finish, unless the price was rock bottom or it was a gun that I really wanted.
if i am buying something like a ruger #1 then yeah spray paint will hurt the value for me, but if i am buying an AK or AR all i care about is whether the gun will shoot straight, and not malfunction, so it is a toss up on what kind of gun i am buying whether the paint job hurts the price.
In my opinion any painted gun is worth less than not painted. If i wanted the gun it wouldnt affect my decision to buy it but I woulnt pay a premium for it.