Economical to pay me to do is likely not the same thing as what I or other people in my situation are/would-otherwise earn. I remember reading an expatriate remarking that one of the best things about living in Africa was that human labor was so cheap that he could do any bizarre thing that came to mind; a job just existing doesn't say much.
(I'm interpreting your last line as saying that the market would create a job for me if I were rendered superfluous or no longer worth employing at my current job; if you mean by 'can' that something like the goverment could create make-work jobs using the wealth surplus, I'll refer you to my reply to Alicorn - we haven't done a great job in the past with helping people rendered redundant by progress or creating a 'leisure society', so I am pessimistic that this might change in the drug scenario.)
All that is quite fair enough - I expect the rest of our disagreement amounts to conflicting intuitions.
There was some talk here about height taxes, but there's a better solution - redefine shortness as a treatable condition and use HGH to cure it. They even got FDA on board with that, at least for 1.2% shortest people.
Unsatisfactory sexual performance became a treatable condition with Viagra. Depression and hyperactivity became treatable conditions with SSRIs. Being ugly is already almost considered a treatable condition, at least one can get that impression from cosmetic surgery ads. Being overweight is universally considered an illness, even though we don't have too many effective treatment options (surgery is unpopular, and effective drugs like fen-phen and ECA are not officially prescribed any more). If we ever figure out how to increase IQ, you can be certain low IQ will be considered a treatable condition too. Almost everything undesirable gets redefined as an illness as soon as an effective way to fix it is developed.
I welcome these changes. Yes, redefining large parts of normal human variability as illness is a lie, but if that's what society needs to work around its taboos against human enhancement, so be it.