If you think the bid is high, I would get at least 2 other bids to compare. But stone is definately not cheap. Our tiny vanity (22x22") was $450.

Do you know how thick the stone was that he quoted you on? That can make a difference too.

If you're not set on a particular colour, maybe you could visit the stone yard and find something cheaper.
One thing to consider about crema marfil is that it is fairly delicate and if I recall correctly will stain and etch easily. We had considered this stone but decided against it.

That's a bit less than $100/sf, if you take out $450 for undermount sink cutouts (I am assuming 3@ $150 each) that's about $70/sf. I don't know how that is for price but you might want to check remnants out. Is it 1 1/4" thick or 3/4" thick? I am paying $65/sf for jet mist granite, 1 1/4" thick, templated, fabricated and installed plus $150 each for undermount sink cutouts and it was one of the more expensive remnants in the yard. My guy had tons of 3/4" marble for much cheaper.

So yes, I think you can do better, but I don't know the pricing in your area. I'd shop around and look for remnants.

We live in a small to mid-sized metro area, so while there are a handful of stone places, they don't have a lot of selection or competition. We have 2 vessel sinks, so no undermount cut out needed, the marble was 1 1/4" and I just got a bid on that style because it was neutral colored and they guy said it was pretty inexpensive.

We are getting much nicer looking granite for the kitchen around $61 sf installed, I was just shocked at the pricing on this. I guess I just assumed it would be quite a bit less than the granite.

You might be able to do better on e-counters with silestone or avanza (engineered quartz), actually. Have you priced it out there? They use local fabricators and may be able to negotiate a better price than you would get yourself? Would be worth a try, anyway.