1999 Chevy Blazer sputtering, missing, lurching

My 99 chey blazer has begun sputtering and popping upon acceleration and lurching a bit in mid cruise. In park when giving it gas it sounds like crap, shudders, etc. We believe it is the spark plugs but my husband is having a heck of a time getting at them to change them. Does it sound like spark plugs to you? If not, what else could it be? The check engine light is on and will flash when it does the sputtering thing. What is the approximate cost of a spark plug change in a garage and would we be foolish to have a garage do something we could do ourselves?