Hello,
Contrary to what velsoftconsult is saying,
searching a mysql DB is not that simple, and while you can replicate the results in one simple query (especially if you change the tables to MyISAM), you don't want that solution on a moderately busy site. Ideally, I would use a precompiled search function, implementing the Levenshtein algorithm to get the results.
Another way to do it would be to use specialized software (there are free options that are REALLY good at this).
Unfortunately, within your budget these are far from being doable.
So:
What I would do, is find you the fastest alternative to using %keyword%. I assume this would involve some PHP at least to separate the words and find the brand by index. (depends on the site of your DB)
The did you also mean can be implemented in 2 (straightforward) ways: either using pspell, or Levenshtein (again) with an English dictionary.