'hardly worthwhile' is correct and usable in written English.
You can use it to describe an activity that you consider of little value or importance. For example, "I found the seminar to be hardly worthwhile; it didn't provide any new information."
Currently, all of the chemical technologies outlined above require the use of energy – in most cases electricity – and it's hardly worthwhile using "dirty electricity" to capture atmospheric carbon.
Online sites allow traders to deal in shares for as little as £5.95 a trade, but effecting a switch can take as long as two weeks, and comes with a charge of £10, which means it is hardly worthwhile.
The rising cost of childcare means that going out to work full-time is now hardly worthwhile for a growing number of "second earners" in middle- and low-income families, a major study will reveal this week.
He has made it clear that he regards meeting with reporters as among the most distasteful of his mayoral chores... His tight-lipped responses during the Q. and A. sessions that follow are so noncommittal as to make the trip across the rotunda often seem to have been hardly worthwhile.
Chris Pine and Ben Foster are two brothers, Toby and Tanner: one smart and one stupid, but both equally engaged in the high-risk business of robbing banks – early in the morning, taking only small-denomination untraceable bills, making it hardly worthwhile for the bank to press charges.
Hence, on the backs of our special needs children, a pathetic and hardly worthwhile attempt to save State Money is being carried out.
Governing California would hardly be worthwhile.
In Kansas City's case, tapping the coach's phone hardly seems worthwhile: they stink.
On a beautiful Labor Day in the nation's capital, it hardly seemed worthwhile to show up for what promised to be an uninspiring day of baseball between teams with poor records and injured stars.
Financial advantages would hardly be worthwhile if the decision to release a prominent terrorist led to a flare-up in terrorist activity.
"The government's message is that you have to save for your retirement, but with the amount you will make it hardly makes it worthwhile if these costs are being taken out.
