Don't let money be your sole motivator. Unfortunately, many talent buyers have limited budgets. Sometimes, it's just shrewd business. Sometimes, it's just a really cheap club owner calling the shots. Often, it's both. The business in the club scene isn't what is used to be. Bands are rarely booked solely as entertainment any more. Bands are most often booked, and usually priced, based upon their ability to bring business to the club. If you have to play for less to "get your foot in the door," do it. If you don't take that initial shot for less money, you may never have the opportunity to prove your self and secure the gig. However, make it absolutely clear that you will expect more pay down the road once you have proven that your band can put asses in the seats. If you don't talk about it up front, you may pigeon hole yourself into a price.
Once you've proven yourself, then you should ask for more money. Rarely will a club owner say, "Hey, you guys are doing really well, you deserve a raise." If you are doing well, don't worry too much about losing the gig for renegotiating your price. The fact is, a club owner is not going to get rid of a band that is making the club money.
