There are more keris acquirable as you have buyers, the great bulk are keris from low craftmanship to average quality often for fair prices, for a better keris you need to pay more when it's fair offered. But never go to buy a keris for it's unproved story or possible use of meteoric content which is unprovable.
There are different opinions to look at a keris, you need to find your own way and be sure that you will do mistakes. How to care about a keris you have bought depend on in which condition you get it. When you get it in good or very good condition you need to do nothing more as to oil the blade from time to time, others need to be cleaned and others need a restoration.
And when you want to believe about a magic content, a keris you care good will show it you!
Regards,
Detlef