I am Head of Training for an FTO/TRTO. I get at least a dozen CV's a week from hopefulls who have shelled out an FI course and are looking for work. The industry is saturated at the moment and likely to remain that way for some time by the look of it. The training organisations are still turning out FI's but the training industry is downturned with the economy and the airlines are not pulling in new candidates at a rate enough to take create the vacancies.
AS a part timer there is work kicking around doing adhoc stuff with experienced pilots, such as differences training and revalidation flights, but not enough to pit food on the table for a full timer I think.
I would think carefully about spending the money, it may be better spent on hour building if your goal is airline work rather than career instructor.