I know what you mean. I guess I was basically after a price list but I didn't want to give them my engine to get one. Other places were happy to provide one and then once the job was commenced we were able to look back at the quote and go, 'ok this bit and that bit are unnecessary but this bit still is and so is this'. As it happened there were a few things that weren't necessary to do on mine and I ended up getting some extra machining done to the head and still came in under the quoted price which was quite reasonable in the first place.
I mean I'm not an expert in engine building or I would have done it myself but I know a fair bit and I'm not an idiot. Nor do I expect anything unreasonable from businesses.
If there is a next time I will pull the engine apart before asking for quotes. If you are careful with your labelling you can take pics and ask on here what's wrong, then when asking for a quote you can get a pretty good idea. One thing you can't do at home is pressure test the valves. I don't know what the proper way to refer to it is but basically they are testing how well your valves seal. If good, leave the head alone, if not, recondition it.
I don't mean to say that either DART or JB are crap. Far from it but I'm just saying that they might not suit you depending on what you are doing exactly and what you expect.