I knew a priest who had been ordained in the 1930’s. When he died, we found a number of first-class relics in his home. We made sure they ended up given back to the parish. In general, over the last 20-30-whatever years, private ownership of first-class relics is pretty heavily discouraged.
If someone wants a second or third-class relic (a personal possession of theirs would be a 2nd class relic; a third-class relic is created by touching an object to a first-class relic), they might go visit a shrine dedicated to that particular saint, and see if they can make arrangements. Especially if someone has, say, a medical condition that makes that saint’s intercession especially pertinent— I know of people who have been able to borrow relics in the past while in the hospital, etc., and experienced miracles.
A lot of places will send out third-class relics pretty readily. (St. Pio, St. Anthony, and St. Jude being the three most common to find.)
St. Michael relic stones are also relatively easy to find. The Diocese of Austin publishes a few articles on the subject periodically, and that always seems to increase demand.