...anyone coming to this thread in the future will find it far more useful if it contained less questioning of motives, language, and feasibility...at least without also including answers to the question.
I have to say I disagree. I think a number of forum users have hopefully pointed out that anyone looking for "low cost calibration" should be beware and really understand what they want to achieve.
In the old adage of 'Fast, good, or cheap – pick two.' applies here.
Things to check before sending off for calibration:
1. If you want adjustment you should explicitly ask for it, and not assume.
2. If you are have adjustment on a UUT that you must ask for before and after. Otherwise how do you know your previous use of the UUT was potentially different readings?
3. Establish the UUT specification that will be used to determine if the instrument needs adjustment.
4. Does the calibration house have adjustment procedures?
5. Is the calibration house using manufacturers recommended verification points (if available) ?
6. What quality standard is the calibration house performing the procedures under?
7. Verify the equipment used for the calibration and uncertainties for the measurements.
You will be surprised about how calibration houses cut corners or are just plain ignorant. Remember there is no 'right way' to perform a calibration, just an agreed way between two parties. Therefore without agreement explicitly in place the calibration house can do what ever they feel right, and hence room to cut corners.
Sorry to cast a dark shadow on all calibration houses, but with competition down to $100 precision DMM calibration something has to give. The trade-offs might be OK for your application.