A Korean drama with poor male lead ......

In addition:

Hogu's Love - male lead is a struggling manhwa writer who lives with his parents and doesnt seem to have success in anything

Ugly alert - male lead is the bread winner who raised his stepsibling and sibling. Parents are dead and he had to work all kinds of odd jobs to fed everyone, then he was incarcerated. When he came put of jail he had no home.

Lovers in prague - male lead is an ordinary street smart detective. He is not really poor but he is very far from well off, especially opposite the female lead who was the daughter of the president

Last Match - very very old drama, released in 1994 and tells a story of poor college students tht had to give up his dreams cause he had to work, but he ended up finding his dream and passion in basketball again

Sangdo lets go to school - the guy is poor and jailed. He also has no permanent job.

Mr.Duke - very old drama, where the male lead delivers water to restaurants

Happiness - the two guys who feel in love with the daughters of a conglomarate businessman are both pretty poor. One is an ordinary salary man while the other is a nomad orphaned poor boxer

Super rookie - male lead is dishevelled and unskilled and most importantly unemployed

couple or trouble - ML is like a mechanic/plumber do all things when you call him kind of guy and lives quite below averga elifestyle with a few orphaned kids

shup up flowerr boy band - ML and his friends are quite poor and they made a band and get recognized

Others dramas: padam padam, east of eden, cheer up mr kim, innocent man, i am sorry i love you, dream high, hello god, miss korea, please take care of young lady, king of ambition

Just wanna point out  some things:

 Healer -  ML was originally poora nd orphaned but by the time the story started he only has to work a couple mor jobs to be able to buy an island in the tropic. So technically he is quite rich. 

Witch romance - ML is actually a chaebol who has taken some time off from his medical studies and wants to live on his own away from all his father money because of a tragedy from his life. So he is really a disguised chaebol

Queen inhyuns man - he is a son of a noble, but his support for the deposed queen inhyun had him be demoted in position. While in the future, anytime he sells the family treasure which was given from aking, he gets  tons of money he was able to buy a car and house. Rhus both timeline he is quite rich.

Because its my first life - i dont think he is poor. To be able take a loan for that apartment of his,  says that he has a stable job as compared the usual poor salary man

What Happens to My Family? - the youngest son is kind of a looser who's in the process of finding a part-time job; a 20-something who hasn't made anything of himself

Surplus Princess - another unemployed male lead

Modern Farmer - group of friends who are in (unsuccessful?) band run out of funds to fund their new album so one of the members decides to use the countryside land he inherited for some kind of get-rich-scheme...idk..it's been a while and idr the plot tbh, but majority of the members were broke lol

Be Arrogant - the male lead's life is a hot mess,pretty much, lol. (Not the best of rom-coms)

One and a Half Summer - not necessarily poor, but the ML is a uni student who travels to China to study abroad and to find the girl that he loves - with a very limited budget. (Warning: bad ending/open-ending)

Plus Nine Boys - set up like the Reply series where each main character gets their own story lines, sub-plots, and decent screen time (kinda like a sitcom), one of the characters is a grown man who lives with his sister and I don't even remember if he was employed. The Lover also had a couple where the man was broke

Master of Study - high school drama with a poor ML (Warning: they tease you with romance, but don't expect much)

Cunning Single Lady - Last but not least, this is a rags to riches story: after 4 year of trying to start up a company/launching a game(? idr) (while being supported by his wife) an aspiring IT developer finally reaches success. The catch? Tired of the husband's constant failure and debt the wife worked to pay off , the wife divorces him just before the burst of his success. Feeling cheated and furious (cause she's still financially struggling) she seeks revenge. This drama incorporates both his before and after wealth lives and is just generally a great drama to watch

cheese in the trap (baek in ho - he is the only reason i kept watching it), school 2013, the day after we broke up, master of the mask (one of the two lee suns).