Despite the ham-fisted linking material the DVD sets are worth the price for the documentaries alone (the best thing Lucas has attached his name to for decades).
I personally consider the series as the extra and the documentaries as the main feature and I preferred much of the series to every Indiana Jones film after Raiders.
I got mine quite cheaply and they are very good value for money at the full price (if you are the sort of person who would watch the show naturally).