$60 may sound very cheap but if someone is wanting a quick sale because they are leaving the country it is probably ok.
Disinfection is 90% elbow grease and 10% disinfectant. Wash and scrub with a bleach solution and then sunlight is one of the best disinfectants you can get. Be careful if the base is plastic as heat will make it warp.
If it does need any painting then a can of spray paint is usually all that is necessary. I have to touch up my show cages every couple of years and I just use cheap spray paint obtained from $2 shops. The bases of my show cages were originally powder coated and that can only be done on base metal, it cannot be powder coated and they do get knocked around on the show bench. I just use spray Gloss Black and for the bars I use Chrome as the Silver does not coat very well. Spray cans are usually water based paint. Just make sure you paint it in an open airy place and let it dry for a couple of weeks at least. Gloss Black is usually the best colour to paint the cages as it shows up the birds inside better and covers better. You will need to disassemble the cage to do it properly, but then you should do that to clean the cage anyway.