You could probably get one that has already been graded for less money than it would cost to send one in.
1964 Proof nickel worth a couple bucks, cost to have it graded $27.50 to $72 depending on whether you send other items in with it or just send it by itself. Do YOU think you should send it in?
@expat is correct. Proof coins are graded as proofs but still on a 70 point scale. MS does not apply to proof coins as proofs coins undergo a different minting process. Hope this helps.
PCGS has a population of only 7 PF70 1964 nickels, and yes, they sell between $750 and $1000 at auction. When you drop to a PF69, the sales price plummets to around $30 to $40. Get a Cameo designation and it bumps it up to around $50. If it'd worth the gamble to you, take it. But the chances of getting a PF70 are slim, and a PF69 might just about cover the grading costs.
Becoming proficient at grading ultra high end coins is a skill that requires studying many existing examples. Spotting the small marks and striking weaknesses that can mean the difference between 68-69-70 takes time and practice. You also need to do a lot of this with the coins in hand as lighting and picture quality can easily give false impressions. IMO, being able to consistently determine ultra high grades is one of the more challenging aspects of the hobby. If you think you understand how to spot these subtle differences, and feel confident this will make the grade, go ahead and risk the $50 +/- and send it in. However, if you're relatively new to collecting and haven't put in the time to learn the ultra high grades, then it may be best to wait. There are lots and lots of really nice looking proofs out there that are only worth a couple bucks. Just my thoughts from 50 years in the hobby
Have you seen a lot of Proof Jefferson’s? I ask because if you haven’t and this is new to you, they will all look perfect like PR 70. This is especially true if you compare the with the Jeffersons meant for circulation. Normally even a low PR60 will show more detail than a higher graded MS example.