I had a couple of thoughts when reading over your post.
First, since you mentioned that your business is “pre-incorporation”, I’m assuming that you conducted your web development business as a sole proprietor, or does this period concern another business altogether?
This naturally entails another question about your structure in Mexico. As far as I know, U.S. citizens are unable to own controlling equity positions in Mexican businesses. Since you apparently lack a U.S. organizational structure, I’m further assuming that you are operating in Mexico either with the help of an agent, or a designated Mexican organization.
Furthermore, I am unclear as to why you need to raise $100,000-$200,000 since outsourced web development projects naturally provide positive cash flow. With other words, the moment you receive a $5,000 retainer/deposit from a client and your cost/benefit ratio is about 40/60 as you say, this would naturally put $3,000 into your pocket.
Advertising also seems to be an unlikely candidate as you obviously have a hard time keeping up with the demand as it stands.
In general, trying to raise $100,000-$200,000 in an equity round is typically an uphill battle and cost prohibitively expensive. For most equity investors, participating in a $200,000 round makes no sense because the administrative efforts and expenses associated with an equity investment would by far outweigh any potential financial returns on such a nominal amount.
Even in the unlikely event that you get the attention of a reputable equity investor for that amount, chances are that such an investment will be to your detriment, since you will be required to relinquish a significant equity position in your business, based on a nominal valuation and insane discount factors. This will translate into costs of capital that will be through the roof.
Sorry, to be the bearer of bad news, but this just doesn’t make sense from where I sit. If I missed anything or if you want to discuss your situation in greater detail, please send me a PM and I will see what I can do to give you a few more pointers.
I hope this helps.