My advice is: professional grading pays off only for high value notes which you would like to sell. This serves as a proof of quality - it is good having an insurance of 15$ if you are buying something really expensive. Many companies will certify only if you send 10+ notes for certification.
For cheaper notes and if you are not planing to sell it doesn't pay off. There was also some controversy about quality of the selves some companies are using - you can search for it and you will find forum posts.
I'm also collecting hyperinflation sets and got Zimbabwe Dollars. For storing notes I use a high quality 100% polyester sleeves - they are more worth than the Zimbabwe notes they hold, however my rule is that I do not buy anything I do not want to preserve.
Since I'm in Europe I'm using Leuchtturm. Good link describing the different types of plastics and holders is here - http://www.panix.com/~clay/currency/sleeves.html
For cheaper notes and if you are not planing to sell it doesn't pay off. There was also some controversy about quality of the selves some companies are using - you can search for it and you will find forum posts.
I'm also collecting hyperinflation sets and got Zimbabwe Dollars. For storing notes I use a high quality 100% polyester sleeves - they are more worth than the Zimbabwe notes they hold, however my rule is that I do not buy anything I do not want to preserve.
Since I'm in Europe I'm using Leuchtturm. Good link describing the different types of plastics and holders is here - http://www.panix.com/~clay/currency/sleeves.html



















