As said above the FI market is quickly becoming saturated. With regard to completing an FI course, firstly its with checking what rate of pay you will be getting. Most FI's I know that aren't airline pilots have a second job to keep their lives afloat. It will certainly take you a long time to recoup your money (but at least you'll get to fly). Consider too if you WANT to do it, FI's that are just 'killing time' are usually not great.
Also worth nothing that with a (probably) global recession looming there will probably be a downturn in GA flying too....