This goes a bit beyond the expense aspect of paying for initial programming/hosting, so please ignore if you feel like it
I've paid tens of thousands of dollars on programming for khimeros, just to give you some kind of idea of costs for that kind of site. Can it be done cheaper? Sure, but you generally get what you pay for. Same with hosting. Hosting is a completely different thing than programming. Again, you can do it cheaply or expensively, but you get what you pay for. How much you will need to spend on hosting depends on how efficiently your site is coded, how heavy your scripts are, how heavy your images are, how much traffic your site gets, etc. I pay nearly $800 a month currently for hosting/backups for khimeros/aluriya. Again it depends on whether you are willing to spend enough to be sure your site has enough RAM, a fast processor etc. If you don't, you'll end up with lag or a site that just doesn't work.
The more you cheap out on programming in the beginning the more money you'll have to spend later and the more headaches you will have. If you just go buying individual scripts from whoever is cheapest, the chances of it all being able to work well together is greatly reduced.
Running a complex site is a full time job and you have to be constantly working to find ways to make enough money to pay for programming, hosting and art, before you ever see a penny of profit. Some months you may not see any profit at all, other months you might do well. You need to be prepared for that and be able to cover costs even during months when you aren't making enough money from the site to do so.
Speaking from personal experience, I don't think that doing all/most of the site art AND running the site is a very realistic goal, even if you don't have a day job/school to deal with. These are the things that cause most sites to fail. People don't realize the kind of time, effort, and money that goes into running a complex site, and thus the site ends up shutting down. The reason given is usually "irl issues". Generally the issues are simply that it's very difficult to have any kind of normal life and still be able to run a complex site unless you are extremely good at organizing your time. Even if you're a fantastic organizer, often there are issues with art/programming features not being delivered when it was promised or with issues that make them unusable without fixing, being on a different time schedule to the rest of your staff, making it hard to co-ordinate (which wastes time), people quitting/disappearing, etc. Plus you need to be constantly vigilant to what is going on on your site so that you can make corrections for unexpected issues that crop up. This makes it hard to make plans for things irl. If you make an appointment or date irl and then there's some crisis with your site, what are you going to do? If you find that you need to alter your sleep schedule to sync with your programmer who lives in Australia in order to get anything done, can you do so?
I don't know if you're planning to run a "hobby site" or a site that you expect to turn into a business. If it's a hobby site, this is perfectly do-able if you keep the scope small, but I think in most cases, owners try for something too ambitious and end up overwhelmed. I would classify a site as a "hobby site" if you are not able/willing to operate it as your primary "day job".