Of course it is worth it... Due to my financial circumstances I had to work throughout my whole degree.. I made sure that for the last two years I had relevant experience, which made studying a lot easier as I did not only stay in the classroom and wrote essays but apply the skills.. I was working 40+ hours a week, alongside full time studying and got a 1st, so it is not impossible.. It's amazing training for postgraduate studying where you will most likely need to work and study... If I didn't have to work probably I would have achieved 80%+ overall as I would do is reading or be the top at the class and get all the prizes and awards, and now that would not have worth it? Why? Because the nice people who got the high marks and the awards and know all the theory has NO skills... They are just now going for jobs such as part time research assistants, support workers and healthcare assistants at the lowest bands e.g. 2 and with salaries of up to £15000... Myself, I have interviews for nearly EVERY job I applied for normally bands 4 -5 with Salary £21000-25000...
If it worth it getting a first will depend on what you want to do.. If you are after PhD, a first means you don't need Masters most of the time... Given the competition a lot of jobs will not consider people with less than upper 2:1...If you are after just a manual normal average job and do not really wish to progress into a specialist or academic position in your field, 1st is probably something that you will not achieve even if you try as you will lack the motivation...
People who say that you can do without university degree are again right.. I lot of people earn good money and never had degrees..However, that depends on what you want to do.. If you want to be manager, you don't need a degree, often work and experience plus professional training are enough, or if you want a building company etc you get my point... However, if you want to be a doctor, or a researcher, or a teacher... you have no chance without degree... so it is hard to give advice is it worth it or not if we have no clue what is that you wish to peruse as a career..