Now that I've done those jobs I know how much I would need to do them, but it may be different for you. That's the point. There are only 5 "normal" positions that I can think of:
You really want the job for whatever reason (money/training/foot in door etc..) and will take a relatively low or average wage.
You know how much the job is worth due to years of experience and intimate knowledge of the specific company so you ask for more.
You need X amount of dollars/vaca/quality of life to do the job because you have other options worth x amount also (take best option).
You don't really need the job but just want to do something, so you are willing to risk asking for more because you don't care that much.
You wouldn't do the job for any amount of money, or it would take a stupid amount of $ to get you to do it.
For instance, I don't like rotating shiftwork, so I would need a stupid amount of money to do that again for any length of time.
If you really want this job, then take the offer unless it is insulting. If you ask for another 3 grand for your bonus, would it be worth you not getting the job? If you don't care too much, then ask. Depends on your position. I think 5000$ bonus sounds reasonable but I don't know how bad they want you, if they will do that sort of thing (risk causing hate and discontent), if you interviewed well, if they really need people, so on and so on. It's a crap shoot man, that's why you only play these games if you have other options, know what you are doing, or don't care too much.