Excel is an extremely useful, extremely complicated computer program that most accounting firms use. An accounting tech program graduate will know how to use this program at an advanced level. This means that his course will have entailed a large amount of hands-on training, putting together spreadsheets with formulas and testing them with raw data.
An accounting technician has to enter a lot of data, especially numeric data. An accounting technician school will refine and hone these skills, teaching you how to use the number pad to the right of your keyboard. This will improve your data entry speed and --- arguably more important for accounting --- your data entry accuracy.
A more broad skill taught in accounting technician courses is the ability to keep books. "Books" are a company's records --- sales ledgers, purchase ledgers, payroll and essentially every other record of how much money is coming in, how much is going out and what its source or destination is. Not only do these need to be accurate, they also need to be laid out in an efficient manner so that anyone can look at them and quickly understand the key pieces of information. An accounting technician school will teach you how to do this.
There are so many accounting tech schools that it is difficult to determine their cost. However, since they are vocational diplomas from community colleges, they do tend to be shorter and cheaper than university degrees. MTI College, for example, has a 36-week accounting tech program. Community colleges cost an average of around $2,000 a year, so you stand to spend much less than you would on a university.