Well, some local supplement companies do sponsor bodybuilders. My girlfriend got 2000$ in cash, plus 2000$ worth of supplements for her preparation for the Canadian championships last year, she also received something like 500-600$ worth of supplements from an independant supplement store BUT she has a website which attracts over 12 000 unque visitors per month, which is more attractive for sponsors... my friend who won the masters class at the Canadian champs (and won his pro IFBB card) had a similar deal with the same company. But these are only for athletes who are already qualified for the Canadian champs (which is actually not an easy thing to do, especially for guys). Some of my friends are "sponsored" by the same company but only receive 500$ in cash and 500$ worth of supplements, but were talking about guys who only reached the provincial level.
Then again, you cannot simply walk in their office and ask for cash. They will not sponsor someone who hasn't competed before. They are not doing this to help you out, but to make money. And to do so they must be certain that the athlete will actually present himself on stage and look decent.
BTW, 2000$ dollars in cash sounds good, but that doesn't even being to cover the grocery bills!!! Contest eating is MUCH more expensive than "regular" eating. For some odd reason "junk" or low quality food costs much less than high-quality/bodybuilding friendly food.
As an example, my daily food bill (for myself alone) is around 30-40$ per day when preparing for a show.. so that's around 210-280$ per week just to eat the proper food. As a comparison, a few weeks ago I had a cheat day and bought enough junk (donoughts, cookies, ice cream, etc.) for a whole army and it cost me something like 15$ and I wasn't even able to eat half of it during the day!
Considering that a solid preparation period (depending on your starting body fat level) lasts anywhere from 12 to 20 weeks, we're talking 2500 - 5000$ only for the food!!! Obviously you would still need to buy food even if you weren't dieting, so that's not all extra expenses, but from experience, contest eating is something like 40-50% more expensive than regular eating... so best case scenario we're talking about an additional 1250 - 2500$ just from food.
Then you must consider the supplements issue. Again, one of the sad things is that if you decide to do a show naturally (no drugs) your supplement bill will actually be bigger than a guy's drug bill (unless he uses more expensive stuff like hGH). For example, your protein powder might come up to 70$/month, creatine 50$/month, glutamine 40$/month, BCAAs (almost mendatory for the natural bodybuilder) 40$/month, various other sups (tribulus, a fat burner, vitamins, minerals, etc.) might run you up and additional 50-60/month. It's quite easy to invest 200-300$/month in supplements when preparing for a show. Now, you don't HAVE TO use supplements. But they sure can help, especially if you go the natural route. So right there we're talking about an additional 600-1200$ for the preparation.
Then you have the little extras like the pro tan (body colour for the show), oild, posing suit, registration fees (100$ for most competitions in Quebec/Canada), show photographer (60$), federation card (60$), etc. If you hire a coach to help you out you will normally have to shell out an additional 150-250$/month. Then you might have hotel/travel fees. When my girlfriend competed at the Canadian World Qualifyer (natural canadian champs) 2 years ago we had to go to Ontario and the journey/hotel and fringe expenses went up to close to 2000$ This year she is competing in both the WQ in Ontario and the "regular" Canadian champs in Saskatchewan... she we're talking at least 4000$ right there. And I don't even want to think about if she wins the WQ and qualifies for the Amateur World championships in Spain... another 4000$
As you can see if you are doing this for the money you are in the wrong sport!!! The only guys/gals who make money DIRECTLY from the sport are the top 10-15 pros in the world and MAYBE some very marketable top level amateurs. Now, many WILL make money indirectly by using their competitive status as a marketing tool to boost their personal training business. But as a rule of the thumb, when you compete at the amateur level each contest you do will cost you money.
One other thing that many people don't consider is that in the last phases of a pre-contest diet you're pretty much a zombie. As a result many guys/gals have to lower their workload/job hours and as a result make less money than they normally would. A guy I trained and who won the Pro Gym cup last year (light heavy and overall) actually dropped out of his university program during his diet because he was unable to focus.
That having been said, if you truely love the sport, you'll do it by passion and money will appear to be very secondary. And if you really want to do it and have the burning desire to surpass yourself, don't let anybody try to convince you not to do it... there will always be some negative energy from peoples around you when you are preparing for a show.