Add Additonal Subgrades

Using BGS, I always use subgrades, and I am not exactly looking at all of the subgrades, but being able to choose a half grade other than 9.5 would be useful. 

I have a card that is worth approximately $4000 in a BGS 9 and $1200 in a BGS 8, but has a BGS 8.5 grade. With some cards, you can split the difference and find a decent price point but the difference is far too vast. I have comped it out on eBay to a few 8.5's in BGS and a few in PSA, but when you go to sell it on Pricecharting, it requests the grade, and sends notifications to those on wishlists based on the price. 

It would be semi-dishonest to put it as a BGS 9 and hurtful for me to put it as a BGS 8. 

Adding half grades should definitely be done, and adding subgrades would be very helpful for selling. 

Thank you for your time!