The plumbing.
Any drain parts not included.
Faucets.

I just saw some gorgeous double bowl Kohler sinks at my reuse center. One was a colbalt blue. They're $50.00 - $200.00.
In a heartbeat if I found one I loved.

If you are planning a new kitchen, then you can plan the reno around using an apron sink, and there will only be a couple of hundred dollars of incidental expenses over a regular sink choice.

If you are retrofitting, then the sink is the cheapest part of the retrofit. You'll have to alter the sink base cabinet to accept the much deeper sink by having the doors remade or removed (with a curtain put in their place) and then build a cradle to support the sink. The extra depth of the sink may require you opening the wall and lowering the waste arm of the plumbing drain as water won't drain uphill. Those costs can approach a couple of thousand in a expensive cost of living location.

Then you'll need new countertops, or to have the stone fabricators to come back out and see if they can recut the existing counter to work with the sink.

So it all depends on what type of renovation you will be doing as to whether or not this is a "bargain" for you.

The only point of resistance would be, for me, that color. It's like a dark greige, and would be hard to integrate into a traditional scheme, considering that there would be a lot of it in view all the time.
Casey