What about checking with area stone fabricators for any granite or quartz remnants? I imagine you could get one templated and installed fairly quickly and inexpensively if one has a stone on hand that you like. They'd need your undermount sink to do the proper cut out. I was pleasantly surprised at how inexpensive for the quality our Toto Rendevouz sinks were. Our local plumbing supply store stocked them. The big box stores would also stock a selection of undermount sinks of course.

We paid about $85 each for our Toto Rendevouz sinks, with Sanagloss (Love!) The price without our contractors' discount would have been about $115, as I recall. We're going with a quartz remnant from a fabricator who said he could get it to us within a week of templating. He's charging $900 for an 85" vanity with two sink cut-outs and backsplash.

Not sure about a CM countertop, but I have had a CM shower and shelf for about 5 years now. Regular use, and it still looks like new. Most large cities have a CM manufacturer. contact them for turn-around time, I would think it would be fairly quick for a little counter. But, I would do CM with an undermount sink. I think the integrated sink in CM would date your reno.

As treasure said, small local fabricator (we have one who is so much cheaper than the average price), will often have remnants on hand. The hardest part will be finding their names/phone numbers. We were recommended our guy by a tile place...that may be a source for you too.

Very nice, kompy! What sink?

Thanks so much for the speedy replies. I'm trying to make the decision today. I was wondering about under-mount vs integrated so thank you for your thoughts on that. I think I will go with under-mounted. I'll call my local granite & stone people to see if they can do a small counter with sink.
Cheers, Alyson

writersblock:
The undermount sink is a Kohler Caxton 2209
Top is Silestone "Lagoon"
Cabinet is Showplace Wood Products: Cherry w/ Autumn Vintage distressed finish.
Beadboard is from Nantucket Beadboard.
Floor is Florida Tile. Classic black and white HEX

The rest of the trim is not up yet.

Thanks. Can't wait to see the finished room.

Hope this reply isn't too late. I remodeled a half bath on the cheap last fall and decided to stick with a cultured marble sink. The old one was 30 years old and still in great shape, it was just ugly. I figured if it had withstood heavy use by two families, it must be durable stuff.

I ordered a custom cultured marble vanity top from Home Depot. It's gorgeous! It has subtle, realistic silver gray veining. Definitely not the cheesy design from the '70s & '80s. I've gotten so many complements on it. It's a St. Paul sink, integral rectangular shape in White Quartz, $230 for a 31 inch top. You can order non-standard sizes no problem.

After installation (remodel still in progress):

The other thing to consider is looking for a solid surface vanity top in a 36". Solid surface can pretty easily be cut by someone who's reasonably handy and has plain woodworking tools. To keep the sink centered, you'd want to cut equal parts off of both sides and then rout the visible side if it's not in an alcove. But, as you can often find solid surface tops at the box stores or sometimes even on craigslist, it's one budget option for those who can handle a saw and a straight edge.