I've been recently shopping a particular core to get some work done and this process is pretty damn similar to dating. So far here are the types of cores that I've encountered:
Core of ill-repute
I'm avoiding you guys like folks avoided the leper colonies back in the Middle Ages. I here rumors and whispers of how horrible you are, taking precious sample, "processing" them and coming up with no results. And then you ask for more sample. Also scouring publications to see who has used you lately and for what turns up jack squat for the past couple of years. Not a good sign.
High $ Hooka Core
You better have some boucou dolla bilz y'all or else this core won't even talk to your brokeass. Your costs are so exorbitant that it might be worth while for me to buy the instrumentation and do the damn work myself.
Waiting by the phone for the Core to call
They seem to have ability to do what you want them to and are reasonably excited. You give them your samples and you wait. And wait. And wait. And wait. You stop counting the days and rather measure the accumulation of gray pubic hair because it takes so damn long to get results back. I'm can't sit in wait by the phone for the rest of my life waiting for you to call with my data, I've got to publish this crap.
The High Maintenance Core
They will do the work and they will do it at a reasonable price, but they're going to make you work for it son. There's no cover sheet for your submittal form, oh that is no bueno. Back of the line Holmes! You better make sure to dot the i's and cross the t's and stroke the ego's of this high maintenance facility
The Easy Core Next Door
This is my favorite core of all and the one that I am going to work with. Not too expensive, this core also understands that your lab is on a budget so they won't order foie grois at dinner. Not only that, you don't have to wait around for ever. This core is pretty easy and will give up the data in no short time. Just give it what it wants. Thank goodness for the easy core next door.