in terms of simply the WGS now vs WGS a little later (I estimate the cost to be <$200 in <10years). The most important questions I would be asking is:-

Am I going to do anything different now with the WGS knowledge that I won't be able to do later (in <10 years)?

Considering I am a live (and still alive) human, will a WGS discovery find a disease that could drastically change my lifestyle? (some - i.e. possible heart problems, possible cancer risks etc)

Procreation status of my family: Do I have kids, will knowing this before I have kids; change the way I have kids (discovery of carrier of a disease). Also applies to biological relatives and their kids. Yes get testing before having kids.

What powerful and useful things have others done with their WGS knowledge? Can what they have learnt be usefully applied to my situation once I have my WGS?

Meta: health - importantly - If this expensive medical test came back with an indication that I should be doing X, would it be cheaper to just do X, and not get the test? (where for some medical test - X might be; live a healthier lifestyle, but might also be install a pacemaker before symptoms, splint the bone without knowing if its a hairline break or a bruise, take extra vitamins, amputate the leg...)

As much as I love data and WGS would give you a whole bunch of data to play with, what would you DO with that data? would it be anything that you can't do in 10 years for 1/10th the price and a similar opportunity cost? As long as you have these questions answered to your satisfaction - do it!