Yes they are but the colour combinations are not to everyone's tastes and they are only in 312 inserts. Get a sample of these from Marlow to see if you like them - David Spragg is pretty good with shipping and you will have them in a couple of days.
If you order directly from ASM, there are a number of excellent edgespots available to the public and even more to Chiptalk members although I am not sure whether these are available as blanks.
Do a search for threads from JimB as there is a special offer page available to Chiptalk on ASM's website - I think they were selling off extra 312 circle square mold blanks a while ago.
Be warned - either of the above will be more expensive than your budget but are infinitely better than dice chips.