Also, I wonder if a certification service such as ICCS certifies notes?
(I used ICCS (only once) to certify a 1951CDN 5c "coin".) Such certification
would include (I presume) comments on the condition.
Do as you wish:
but IMO: although these replacement $20 notes aren't common, they aren't particularly rare with printing
numbers in the 400,000 range. If you are going to pay for third party grading than you should think hard
about the potential demand of the note you're about to grade, and whether the cost to grade them is worth
the investment.
Many collectos don't consider the demand of a note and that could be their biggest mistake.
They often look at the number of notes printed and from there - presume its rarity/demand equates the catalogue value.
The reality is-- you should also think about the number of collectors collecting a certain denomination, series, special numbers, errors, etc. Many factors come into play. For instance, I believe there are many more collectors who collect only low denominations ($1,$2,$5) rather than higher denominations ($50,$100,$1000). Presently, in Canada at least, it appears as if there's more special number collectors than there are error collectors.
On another thread a collector has asked what his solid radar note would be worth. He hasn't stated a condition but for a lower denomination (solid radar) it may be worth TPG (3rd party grading such as ICCS). The same would apply to scarcer notes such as asterisk devil faces, 1935/37 radars, short prefixes, or rare signatures.
Finally, if you're thinking about TPG, you should also consider how you're about to sell the said notes (eBay, live auction, yahoo, etc). For some collectors TPG authenticates and boosts the notes value. Others avoid TPG notes.